Be sure if you recharge the system yourself, rent an A/C gauge at AutoZone (no, or limited cost). I know of a few people that had bought kits and the gauge was off, so they put too much in the system and thus, didn't work and caused even more problems. If you take precautions you can safely do it yourself for half the cost. On the other hand, if the dealer screws anything up, you can take it back instead of kicking yourself in the pants from running too much pressure and causing more problems on your own. If you think it's a risk you're willing to take, by all means and go ahead.
I would have myself believe that I'm rather intuitive when it comes to vehicle maintenance. I can do nearly anything mechanical including rebuilding engines, replacing gaskets and 4x4 hardware, but I won't go near the A/C system without proper training. R134a refrigerant is dangerous if you don't take the correct precautions.
'11 Ram SXT 4x4 quad cab - 5.7L V8; 128,200kms
'09 Malibu 2Lt 3.6L - 140,000kms purchased 1 March 2019
'06 Pontiac G6 GT - 3.5L V6; 162,000kms (rear ended 15 Feb 2019, and given totalled title by insurance)