It is a fun business if you aren't one of the guys pulling parts. I was the car buyer so I really had fun spending money and got to see all the inventory before anyone else.
At the salvage we couldn't find enough good used 4.7L V8 engines to supply the demand there was. We salvaged a lot of nice vehicles that needed 4.7L engines. Based off my experience there I wouldn't want to be in that boat.
Impound sales is where I pick up a lot of goodies if you aren't in a hurry. Co-Part is best used if you have a buddy with an suto dismantlers license because as a private buyer they soak you with a lot more fees.