The build looks solid from a parts perspective...
Is the barrel threaded for a muzzle device? I don't see one listed, The handguard used can add a bit of cost/value to the rifle as well.
Just know that resell on rifles is very, very low right now due to the post panic glut. There's always a sucker born everyday who will pay top dollar for that "custom" AR15, but most buyers in the know are aware that ARs are a dime-a-dozen right now.
Take the price you paid for all the parts, knock off 30-35% or so, that's what you could likely sell it at right now. Of all the things in my home, the last thing i'd consider selling right now is my ARs...prices are just too low. This should change with the next presidential election cycle, and even more so after/if Hillary gets elected.