I still have two cars that use R12. When the A/C guy who did my R12 service finally stopped working on those systems, I decided to take a look at doing it myself. I shopped around on Craigslist and found a like-new Robinair recovery/recycle machine for $350. I also picked up a vacuum pump from the same guy. I had some R12 in 'stock', but I let my car friends know that I'd like a bit more. Before I knew it, I'd bought 50+ pounds of the stuff, along with a supply of both kinds of oil from two different people, dirt cheap. The way I figure it, I'll never have to worry about charging my own systems again, and, if I sell those cars; I can still get at least some of my investment back by selling my machine and peripherals.
Not that you'd want to do that, but... if you want to stay with R12, ask around at cruise-ins and car shows. The people who still can handle R12 recharges are generally old guys with old cars!
Edit: I forgot to mention that, if you want to simply try adding refrigerant to your system, there are products like "Freeze12" still available at the retail level. These products are different formulations of chloroflorocarbons (sp?) that aren't governed by current Federal regulations. The warnings on the cans say not to mix them with R12, but my opinion is that that's a CYA statement; since my friends and I have been mixing them since they've been on the market and have yet to see any detrimental effects...
SL