the price for a 2.5 ton unit replacement is a little high, but find out if it is only the ouside unit or the inside coil also, the wholesale price that a company can buy one is about 600 dollars,,, but you have about 6 hours labor, at about 60 bucks an hour, so thats around 950 to a 1000 , be sure they replace both the inside and outside coil for it will work proper. i would probly charge somewhere at 2600, if it is an easy install, but how bad you need it is the question, if no one else will come, thats not that much higher for the comfort.

That quote sounds allright, most companies quote higher for a replacement using the same electric and ductwork. $4500 and up

But by all means get 3 or 4 more quotes and don’t get caught up in the 15 seer rage they are way overpriced.