Since your upper is no longer an EAG upper, I would ignore the EAG designation and base your price off of the configuration here
http://www.bravocompanyusa.com/BCM-1...4bfh-c4-12.htm
That is the same upper you have now with the $189 BC pinned and welded. your total new would be $1042 take 15-20% for being used as IG stated, you're looking at $830-880. Stating it is an EAG upper is what is hurting your pricing unless you had it with the Larue handguard setup. Just consider sell it as BCM BFH 14.5 midlength with Centurion 12" rail and BC pinned. you would be crazy to take only 500-600 for it IMHO.