I bought a DPMS LR308 with a slick side upper receiver. The rifle has about 60-100 rounds through it. I am considering changing over to the upper receiver with the forward assist, ejection port cover, and shell deflector. Is there any market for a used upper like this, or would I be stuck with a useless part? If it is a sale-able item, what would be a fair price to ask. I'm not looking to hose anyone, but don't want to just give it away either. Catalog price for a new one is $125.00. Would a price of $75.00 be about right? Thanks..