Why Two Contractors Quote $5,000 and $11,000 for the Same 3-Ton AC

One contractor quotes near $5,000. Another quotes $11,000. Same house, same 3-ton straight-cool split system. Neither is necessarily wrong — and understanding why is the most useful thing you can learn before signing anything.

Even the Published Cost Guides Cannot Agree

When we built our cost data, we pulled every recent national source we could fetch for installed AC replacement pricing. They split cleanly into two camps that disagree by 40-50% at the same tonnage.

The low band, for a 3-ton system: NearbyHunt at $5,000-$9,000 (May 2026), FixUpFirst at $5,500-$8,500 for its 3-3.5 ton bracket (updated May 2026), and Team Enoch at $5,500-$8,000 for 2.5-3 tons (2025).

The high band: ServiceAgent at $7,500-$11,000 for a 3-ton (May 2026), HVAC Services Pro at $2,500-$3,000 per installed ton — $7,500 low, $10,500 average on a 3-ton (April 2026) — and Atlas AC Repair’s full-HVAC averages landing around $9,100-$10,000 at 3 tons.

That is not a rounding disagreement. It is a 40-50% gap on the same size system — well beyond the 25% agreement bar we require before calling a figure corroborated. So we did the only honest thing available: we widened our published 3-ton range to $5,000-$11,000 so it covers both bands, and we label it an estimate, not a corroborated fact. Most cost sites pick one band and present it as settled truth. We think showing you the disagreement is worth more than hiding it — because if the publishers whose whole job is averaging real prices spread this far apart, your individual quotes will too.

Here is what actually moves the number.

Driver 1: The SEER2 Efficiency Tier

Efficiency tier is the single biggest legitimate multiplier. Against a 14.3 SEER2 code-minimum baseline (1.0x), our data uses 1.15x for 16-17 SEER2 and 1.35x for 18+ SEER2. On the 3-ton base range, that means roughly $5,750-$12,650 at 16-17 SEER2 and $6,750-$14,850 at 18+. If one quote is for a code-minimum system and the other is for an 18+ SEER2 variable-speed unit, a several-thousand-dollar gap is not padding — it is a different product.

Driver 2: Where You Live

Labor is local. Our state cost index treats half the job cost as fixed nationally (equipment, materials, overhead) and scales the other half by what HVAC mechanics actually earn in each state, using BLS wage data for the trade (SOC 49-9021, May 2025). Florida’s mean wage of $57,310 against the national $64,780 produces a 0.94 index; Arizona’s $60,900 produces 0.97. Same system, same tier — a Phoenix install prices a few points higher than an Orlando install purely on labor. Across states the spread gets wider, which is why a national number quoted with no location attached is already suspect.

Driver 3: The Permit

A legitimate Florida quote includes the mechanical permit — required statewide for every changeout — at roughly $75-$400 depending on jurisdiction (an approximate range from third-party fee summaries; confirm locally). It is a small line item, but a quote that omits it entirely tells you something about how the contractor operates.

Driver 4: Your Ductwork

Two contractors can look at the same attic and scope it differently. One quotes a box swap and leaves your ducts as-is; the other includes sealing, repairs, or modifications the system genuinely needs to deliver its rated performance. The second quote is higher and may be the better value. This is the driver most likely to explain a large gap between otherwise-similar bids, and it is exactly the line item to make each contractor put in writing.

Driver 5: The Refrigerant Transition

The industry is moving to A2L refrigerants like R-454B, and that transition costs money right now. Green Leaf Air pegs the R-454B transition at roughly 5-7% added to split-system totals; AC Direct’s Dallas data reports equipment up 8-10% from the A2L changeover. On the service side, R-454B runs $60-$90 per pound while R-410A sits at $50-$150 per pound installed (an estimate — sources’ midpoints span $65-$115, with prices up 30-50% since 2024 on AIM Act quota cuts). A quote on new A2L equipment carries a real premium a competing quote on older-generation equipment may not.

Driver 6: Rebates

Florida’s utility rebate landscape is among the strongest in the Southeast, and whether a contractor nets rebates into the quote changes the bottom line: FPL offers a $200 instant credit at SEER2 15.2+, TECO pays $40 at SEER2 15.2 or $550 at 16.2, OUC pays $45-$1,150 depending on tonnage and SEER2, and JEA pays $200 for qualifying ENERGY STAR systems. Duke Energy runs a program too, though its amounts are unverified on Duke’s own pages — confirm before counting on it. Two quotes can differ by hundreds of dollars simply because one already reflects a rebate and the other leaves you to claim it.

How to Use a Range to Sanity-Check a Quote

A published range is not a price — it is a filter. Use ours ($5,000-$11,000 for a 3-ton, estimate) like this:

Get 2-3 written bids, and make each one itemize the same things: tonnage, exact SEER2 rating, refrigerant type, ductwork scope, permit fee, and any rebate already applied. Then compare against the range. A bid below the floor should make you ask what is missing — is the permit in there? Is the ductwork scoped at all? A bid above the ceiling should be explainable by a named driver: an 18+ SEER2 tier, real duct repairs, HVHZ requirements. If a contractor cannot tell you which driver puts their number where it is, that is your answer. The spread between quotes is normal. An unexplainable spread is not.