The cost of an AC compressor depends on the size of the unit, where you live, and who is going to install it. In general, a 2.5 ton compressor will cost between $1000 and $180…0 depending on the manufacturer and installer. One user said: You can find a 5 ton compressor for under $1000 online. If it's for a car, 200.00 & up/re manufactured.