This is always a two way argument. Yes there are people out there who only add a few parts and call it custom, then try to sell it at a high price. But I have also seen people that have really spent a lot of time and money building absolute beast's, yet get lowballed by people that either don't have a clue what they are buying or want to buy gold with buttons.
For example; there was a guy last year on another forum selling an Inokatsu STEEL M240B for £900, which is a bargain when it cost £1600 New and was unskirmished. Yet two lads made a thread about what a rip off this guy was, and that it was overpriced and that you can get the same thing for $300 from the abroad. Well most people know a $300 echo1 to a full steel Inokatsu is a big difference.
But my point is; where is the line drawn between an over priced gun, or someone just wanting something for nothing?
At the end of the day, as everyone else has said, if your not happy paying that price, give a offer, if not accepted, walk away. It's no biggy is it?