On my 66 C10, an American Autowire complete kit costs me right at $800 delivered. A Vintage Air Generation 5 AC system was just under $2000 delivered. Both kits are excellent, very complete and diy friendly if you’re mechanically inclined. Not sure what to say about labor charge if paying someone else to do install.

1966 C-10 Short Stepside
HiPo
Step-by-step ~ and on-going resto build
in the Project Journals