R12 is still available for those with a 609 license. For $15 and an hour or two of work you can get the 609 license with an open book test at www.imaca.org.

R12 is coming down in price while 134 is going up in price. I bought it last year for less than $15 per pound while 134a was pushing $10 per pound. It could very well be that this year the prices will equalize. It now is just not worth converting an R12 system to anything besides R12.

Good luck,