The St. Louis replacement-window market is built around the in-home sales appointment: every major company we checked in October 2026 gives a price only at a visit, and at least one states in print that its discount is good only at that first visit. The way to compare quotes in that market is to refuse to decide in the room, get every quote in writing on the same scope, and compare the per-opening installed number — not the headline percentage. This guide walks the lines, and the worksheet at the bottom is the kitchen-table version.
Why is the price only good today?
Because a price that expires when the salesperson leaves prevents you from comparing it. That is its purpose. The wording in this market, verbatim from public pages in October 2026:
- One national chain's St. Louis page: "Buy 2 Windows, Get 2 FREE" plus "40% off windows," with the offer "valid only at the initial in-home estimate."
- Another: "Buy 4 Windows, Get 4 FREE!" and "$1,000 OFF Your Project," on a page whose call to action is a free in-home consultation.
- A third: "Save 30–50% off your new window purchase," "Payments from $199/month," with a four-window minimum and an offer that "excludes labor."
- Several others simply require the visit: "schedule an in-home price quote," "give you a quote on the spot," "we'll visit your home to accurately measure."
None of this tells you what a window costs. The free windows are priced into the paid ones; the percentage is off a list price nobody sees. The only comparable number is the final written total divided by the number of openings, for the same material and method.
What a comparable quote has on it
Ask every company for a written quote with these lines, and do not compare until you have them:
| Line | Why it matters |
|---|---|
| Each opening listed with location and size | A "14 windows" total hides that one quote skipped the basement |
| Install method per opening — insert or full-frame | 25–60% price difference; the biggest reason two quotes differ. See insert vs. full-frame |
| Product line and series | "Premium vinyl" is not a product; the manufacturer and series are |
| NFRC ratings — U-factor, SHGC, air leakage | St. Louis is North-Central: U ≤ 0.25, SHGC ≤ 0.40 is the target. See performance ratings |
| Glass package — low-e, argon, pane count, tempered where required | Triple-pane adds $120–$250 an opening; make sure both quotes have the same |
| Lead-safe work on a pre-1978 house | Required by law; a quote without it on a 1920s house is from a firm not doing the job legally. See lead-safe replacement |
| Exterior trim treatment — brickmould retained, replaced, or wrapped | "Capping" in aluminum coil hides rot and fails historic review. See the brick guide |
| Disposal, cleanup, permit, CRO review | Small lines, but their absence tells you something |
| Exclusions | Lintel repair, plaster, painting — stated, not discovered |
| Lead time and install window | Weeks, not "soon" |
| Price validity | 30 days is normal. "Today only" is a tactic |
| Financing terms — APR, term, deferred-interest rules | See below |
| Warranty — what is covered, for how long, transferable or not, labor included or not | See below |
Financing: the published numbers
Window financing in St. Louis is mostly third-party consumer credit arranged by the window company. As published on company pages in October 2026:
- 0% for 36 months through a Wells Fargo retail card, 28.99% APR after the promotional period (terms as of August 1, 2025) — Window World of St. Louis.
- "Pay Nothing for a Year" through Upgrade, 29.49% APR deferred — Champion Windows of St. Louis.
- No-interest promotion at 17.99% APR, "$0 down," payments "from $199/month" — Window Nation, St. Louis.
- 18 months no interest with payments, or 6.99% for 60 months (October 2026 promotion) — Lakeside Renovation & Design.
Two things to understand about deferred-interest plans: if the balance is not cleared by the end of the promotional period, interest is typically charged from the purchase date on the original amount; and the plan's cost is carried in the price whether or not you use it. A credit-union home-improvement loan or a HELOC is usually cheaper money. We do not arrange financing; our quote is the cash price.
What "lifetime warranty" usually means
Read the warranty document, not the brochure:
- Whose lifetime? Often the original purchaser's ownership of the home, with a reduced transfer to the next owner.
- What is covered? Manufacturer's defects in the frame and the insulated glass seal — typically. Labor to replace a failed unit is often excluded after a short period, or is the installer's separate warranty.
- Glass breakage? Usually a separate, shorter term, or not covered.
- Who honors it? The manufacturer for the product, the installer for the installation. If the installer is a franchise or a brand that leaves the market, the installation warranty leaves with it.
Ask for both documents and compare the labor coverage; it is where the real differences are.
Red flags, in order
- A price that changes if you do not sign now.
- A "free" count — windows, months, anything — with no per-opening installed number.
- No install method on the quote.
- No lead-safe line on a pre-1978 house.
- "We don't need a permit" with no mention of which jurisdiction you are in. See permits.
- A tax-credit line in 2026. There is no federal window credit for property placed in service after 2025. See tax credits and rebates.
- "Capping" or "wrapping" as the standard trim treatment on a brick house.
The worksheet
Download the quote comparison worksheet — one column per company, one row per line above, and a per-opening calculation at the bottom. Fill it in with the written quotes on the table, not with anyone in the room.
Frequently asked questions
Is it rude to tell a salesperson I am not signing today? No. It is the only sane answer to a price that expires tonight.
How many quotes should I get? Three, on the same scope, with the lines above.
Your prices are public. Doesn't that mean you are the most expensive? Our planning bands are on the cost guide; the quote is exact after a measure visit and does not change if you take two weeks to decide. Compare the per-opening installed number and see.
Can I negotiate? You can ask any company for a better number. The honest version of negotiation is matching scope and letting the per-opening figures speak.
Next step
Window replacement — a written quote, valid for thirty days, after one measure visit. Related: the cost guide · the complete St. Louis guide.