This Senco SN70XP is a bargain IF you have the needed part or buy it. On ebay for Buy it Now $25.00 + $13.14 to Ship.
The part needed is the back plate # FC0227 there is one on ebay for $50.00 delivered.
If you bought both, you would have a super duty framer for under $100.
I have quite a few parts and kits for these