Freon isn't bad, you can get it for $10/12oz can (R134a) at Wallymart. 2 cans will fill most systems.
I bought the A/C service manifold at Harbor freight and have done a few cars with it (you need to do the R134a port conversion first, just the two screw-on fittings). You can even get an HF vacuum pump to pull a vacuum before charging. I'm sure I didn't get all the amounts right, but suction and discharge pressures look good and the system blows cold air! Beats paying $300+ for service like you do at most shops. Just have to make sure you also get a somewhat apropriate amount of oil into the system.
Basically if i'm charging a dead system in an unknown state, i just slowly start to put a can into the system, then stop and listen for leaks. You waste a little freon, but you can usually find the leak (if its big) pretty reliably. And if its a slow leak, depending on HOW slow, a charge may last you a couple months, which will get you through a summer. Thrifty comfort
