Air conditioning shops still have R-12 available for older systems, but it is getting more scarce and thus, more expensive whenever you are having an older system recharged.
Plus, it has to be reclaimed properly (another added cost).
You may have a leak in your system which could require parts and labor from a few hundred to a few thousand $$$. If the leak is bad enough (as mine was in the past), recharging the system will get you through to the end of the week, only to have hot air again by the following weekend.
If you are not planning on keeping the car, don't invest any $$$ in the A/C system, and get a plug-in fan. Sorry.
Maybe others have a more optimistic viewpoint?
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car