Between various vendors (ghostguns, eBay, GB, etc) I have sourced all ORM parts to complete an ss80 (-43 clone). Ang gun shows around likely to be able to beat that for OEM price?
There is a guy at most of the local shows who sell P80 parts and OEM components. He buys from the same places you sourced, so he is NOT cheap. The best bet that I have found is Ebay. Also the Glock store may not be the cheapest, but usually has everything in stock if you don't feel like waiting. Run like hell from a place called 21 sports ( if they are still in business).
When the craze first hit, if could you find the part, you bought the part....