Sounds like a good price on the part's. Don't forget to add oil before your done. As a general rule, with out looking up the spec, you probably want to add 2oz. for the compressor, 1oz for the condenser, 2oz for the accumulator, 1-2oz for the leak and age of the system. I think the capacity is around 8-9 oz. It would be a shame to lose a compressor in 3 months because your system was low. All this is assuming the shop didn't add any and the DIY kit you used initially didn't add any to it.