$35 a lb for R134 seems way high.... I've heard it's been going up, but $35 a lb?
You might want to look for a dedicated AC service place, preferably one that advertises 19.99 refills
There is one locally (ok, Allentown PA) that had a 300D parked there a lot, assuming it was either an owner or an employee....
I had my indy shop fix the 300SD's AC a while back and it cost about $400... and I think the R12 was around $48 a lb...

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Bob Roe
Lehigh Valley PA USA
1973 Olds 88, 1972 MB 280SE, 1978 Datsun 280Z, 1971 Ford T-Bird, 1972 Olds 88, 1983 Nissan Sentra, 1985 Sentra, 1973 230.6, 1990 Acura Integra, 1991 Volvo 940GLE wagon, 1983 300SD, 1984 300SD, 1995 Subaru Legacy L wagon, 2002 Mountaineer, 1991 300TE wagon, 2008 Murano, 2007 R320CDI 4Matic 52K, some Hyundai, 2008 BMW 535xi wagon, all gone... currently
2007 Honda Odyssey Touring, 2014 E350 4matic