In Port St. Lucie, Resale Sellers Are Competing With a Builder's Rate Sheet

Suppose you sign a contract on a Mattamy home in Tradition this month to get the advertised 3.99% rate. Who chooses your lender and your closing agent? Mattamy does. Under the terms of its Port St. Lucie 2/1 buydown, the buyer has to finance through Mattamy Home Funding and use the closing agent the seller selects. The contract has to be signed between October 2 and October 31, 2026, on a "select" home that closes by November 30, 2026. You don't have to use either one to buy the house. You do have to use both to get the rate.

That one condition explains how Port St. Lucie's market works this fall. Builders here compete on the monthly payment. A seller listing an existing home in the same part of the city is up against an offer the official market statistics barely record.

Builders Are Selling Financing

Here is what three national builders were advertising for Port St. Lucie in early October 2026, along with the conditions attached to each offer.

Every one of these offers is limited by home, by date or by lender. "Up to" and "select homes" mean the headline number applies to some homes in a community, so the actual terms on a given house come from the sales office.

What the 3.99% Is Worth in Dollars

Freddie Mac's weekly survey put the national average 30-year fixed rate at 7.28% as of October 1, 2026. That was up from 7.03% the week before and 6.34% a year earlier. A buyer financing a resale home with an outside lender starts from somewhere near that average. A buyer taking Mattamy's offer starts more than three points below it.

Mattamy's disclosure is based on a $472,000 purchase with a $424,800 conventional loan and 10% down. Here are approximate principal-and-interest payments on that same loan amount. They leave out taxes, insurance and any association dues:

• At 7.28%, about $2,906 a month
• At 5.99%, the permanent rate under the promotion, about $2,544
• At 4.99% in year two, about $2,278
• At 3.99% in year one, about $2,026

Add up the gap between the 5.99% payment and the two discounted years and you get roughly $9,420. That almost exactly matches the up to $9,418.68 Mattamy says it will put into the temporary buydown fund at closing. So the fund only pays for the first two years. The bigger, longer-lasting advantage is the 5.99% rate itself, which Mattamy says it locked in through its affiliated lender for a pool of funds. The rate lasts until that pool runs out or the rate expires. On a $424,800 loan, the difference between 5.99% and 7.28% comes to about $362 a month, every month.

The K. Hovnanian listings show why the APR matters as much as the rate. At Aspire at Port St. Lucie, the Aegean at 1902 SW Beauregard St. has 4 bedrooms, 3 baths and 2,350 square feet. It is listed at $574,995, down from a displayed $608,105, with a 4.99% promotional rate and a 7.406% APR. The same floor plan at 2474 SW Mercer St. is listed at $544,995, down from $603,465, with a 5.5% rate and a 5.854% APR. The home with the lower rate has the much higher APR. The page doesn't explain why, so ask the lender before you compare that home against a resale on rate alone.

The Seller's-Market Report Leaves Builder Sales Out

MIAMI REALTORS' August 2026 report for St. Lucie County shows a calm resale market. The single-family median was $402,500, up 0.63% from a year earlier. Single-family supply stood at 4.9 months, which the report calls a seller's market. TCPalm reported July results in similar terms on August 24, 2026, calling it a seller's market on the Treasure Coast.

A line in the same release explains the gap:

"The sales total doesn't include South Florida's new construction, pre-construction and condo conversion sales because they are largely not reported in the MLS."

So the 4.9 months of supply counts resale homes against resale buyers. It mostly doesn't count the move-in-ready homes in Tradition, at Veranda Preserve or at Aspire, even though resale sellers are competing for the same buyers. The other resale numbers in the report fit that pressure. Single-family sales fell 6.53% year over year in August 2026, from 475 to 444. Sellers received a median 96% of their original list price. On a $420,000 asking price, that's about $16,800 below the first number on the listing.

Financing is the other part of the picture. Cash made up 25.2% of St. Lucie County single-family sales in August 2026. That leaves about three in four single-family buyers using mortgages, and those are the buyers a builder's rate offer is built to reach.

The release puts the median time from listing to contract for single-family homes at 54 days in August 2026, against 64 days a year earlier, though its own wording calls that change an increase, so the direction is unclear from the report. The 96% figure is clearer. It describes sellers who are getting deals done by pricing to the competition.

Builders Want Finished Homes Closed by Thanksgiving

The City of Port St. Lucie's permit numbers help explain why the incentives target homes that can close soon. The city issued 4,069 single-family permits in 2023, 3,525 in 2024 and 2,899 in 2025. In 2026, through July 26, it had issued 1,192 single-family permits and 1,173 single-family certificates of occupancy. Certificates of occupancy are issued for completed homes, and this year they are being issued at almost the same pace as new permits.

Our reading of those numbers is that builders are starting fewer homes than in recent years and working to sell the ones already built or close to it. The offer terms point the same way. Mattamy's rate requires closing by November 30, 2026. The two Aspire homes above are marked "Ready in October." A completed home with no buyer costs a builder money every month it sits, and a rate buydown is one way to move it before year-end.

For a resale seller, the timing matters. Through late fall, the strongest competition comes from homes buyers can move into right away, with deadlines that push buyers to commit within weeks.

What This Means for a Resale Listing

A resale seller can't match a builder's affiliated-lender rate pool. A seller can lower the price or negotiate concessions with the buyer. Both should be measured against the payment a buyer could get on a nearby new home, as well as against other resale listings. When a resale buyer is at 7.28% and the builder's buyer is at 5.99%, the resale price has to make up roughly $362 a month in principal and interest on a $424,800 loan before the two homes cost the same each month.

Resales still have advantages, and builder fine print is where they show up. A resale buyer can choose their own lender and closing agent. There's no contract window to hit and no requirement to pick $200,000 in options to get a $100,000 credit. A resale listing that shows a buyer the full cost of each path will do better than one that only competes on list price.

For buyers comparing the two, ask these questions about any builder offer before you sign:

1. What is the APR, and why is it different from the promotional rate?
2. Which specific homes qualify, and does the one you want?
3. Does the offer require the builder's lender, the builder's closing agent, or both?
4. What is the contract deadline, and what is the closing deadline?
5. Is the credit cash toward closing, or limited to options and upgrades?
6. What would your rate be with your own lender, so you know what the incentive is actually worth?

Quick Answers

Does a 3.99% buydown mean 3.99% for the life of the loan? Under Mattamy's terms, no. The rate is 3.99% in year one, 4.99% in year two and 5.99% after that.

Is St. Lucie County a seller's market right now? Counting resale homes only, the August 2026 data shows 4.9 months of supply, which the association calls a seller's market. That data largely leaves out new-construction sales, which are the main competition for many Port St. Lucie resales.

When does September data come out? The most recent association report as of early October 2026 covers August. Builder offers change faster than that. Several of the offers above expire in October.

If you're pricing a Port St. Lucie home with a builder's model center down the road, Evan Sophir can show you what buyers are being offered there and build your price and marketing around that payment comparison. Request a Free Market Strategy & Media Plan and we'll put the numbers side by side before your listing goes live.

This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.