Mainstream has a variety of guns an ammo, and very knowledgeable about them, however they are clueless about the actual value of the rest if the items specifically guitars.
I found an acoustic electric I liked, an ovation GC057M-5 Celebrity. They had a $329 price tag on which seemed very high. After a few minutes online I found out they sell in good condition for about $150 on guitar centers used instruments website ( http://used.guitarcenter.com/usedgear/index.cfm?page=1&sort=price&dir=asc&srch&category=37&q=ovation). I watched their prices for two weeks just to verify the price.
Now they sell in good shape at $150, and theirs was rough. A lot of dents, cracks and scratches rusted strings and tuners. In that condition its worth at best $100, it needed work. I offered $150 because it was a local business. The guy got very defensive and angry immediately. He told me "you're not hitting the right buttons, you don't know what you're talking about". I brought up the website to show him the 3 listings at $150, but he told me to go buy it somewhere else.
Calling your customers liars and acting like a child is not a good way to do business. Do some research before you overpay for items and treat your customers with respect. read more