[Bob Kontak]

If they evacuate and pull a vacuum to make sure it is leak free that is not an unfair price.

Takes about three cans of R12 (about 32 ounces) so at, say $30+ per 12oz can, it's under $100 for labor. They most likely buy in volume and they will have 30 pound containers of R12 so some margin will be made on the Freon.

Ask if you will be getting fresh R12 or recycled R12 (scavenged from other cars). I do not know if they are even allowed to use the used stuff but if they convince you they scrub out the contaminants, might be just fine.