hey buddy, I  do hvac for a living, it sounds a little high for 134, but a bit low for r12,,You cant even buy r12 anymore and if you do a 30lb can costs me over 1200, didnt think you Michigan folks got hot,,rd

I have been using Evirosafe ES-12a as a drop-in replacement in my R-12 systems for about six years now.  I have a friend who is a refrigeration engineer with Lenox and he swears by Freeze-12 for his cars so I assume he knows what he's doing.  The only reason he doesn't use the real r-12, since he can legally buy it, is that if he does develop a leak, its a lot more money to lose not to mention bad for the ozone layer.  Obviously, the real stuff can't be beat as long as you can keep it in the system.  Anyway, here is where I buy the ES-12a and they sell r-12, r-134 etc. too, so you can compare prices on their web site:

http://www.autorefrigerants.com/

HTH