A/C Help. Dual Pressure Switch and Recharge.

[ShaunakaRichard]

So today I tried to use my A/C for the first time since its gotten warm. To my surprise, it didn't work. After a lot of testing I found that there's no continuity at the dual pressure switch. So that seems to be the culprit. I know to replace it I'll have to vent the system. So my question is anybody know how much it'll cost to recharge the system? I've also heard about a new freon R-34 I think. How much cheaper is this stuff and does it work? I spent a lot of time getting A/C onto my SR last summer without unhooking the compressor to keep it sealed and making up my conversion plates and I want it to work damnit.