I have no refrigerant in the car and have a leak atm.  What are people's experience of most likely bits to fail and need repair/replacement?  Approximate costs for these bits would be helpful too!

Is it possible to diagnose the leak myself, if so how?  A dye and a UV light?

I'm more than happy to take it to my local indy to sort it out, but that won't happen for a couple of weeks, plus it'd be nice if I had a source for parts readily lined up.

Cheers.