Herb - R12 is no longer manufactured in the USA,
but R-12 IS available for purchase. I've seen 30lb tanks on eBay go for ~$15/lb. Typical price is $20-$30 per can or pound, which translates into maybe $50-$60 for a complete charge in your car (after fixing leaks & evacuating). Given the labor involved with flushing for a retrofit, and/or the cost of new components, $50 is downright cheap. What part of "penny wise but pound foolish" isn't clear? It's not like R-12 costs $100/lb and the alternatives are free....!
