Find what you want, then search to compare prices. That will give you about a average going price.
i know but i mean like is there an easy way to find out how much a geo 2 cost or how much a dm10 cost, stuff like that? or do i need to do my own research.
Not really. The problem there is that pricing is VERY fluid in the gun market, and it varies depending on a lot of factors. It's always best to browse around when working on prices. You'll find some great deals that way!
The MCB Blue Book is great for older guns, but is vacant for the newer ones. Even then, there's a lot of subjectiveness and factors that go into pricing something. Does it have a bunch of upgrades? Are there spare parts that go with it? Does it have something in it that could only be had if you were part of a factory team? Is there a real history to the gun (ie, the Jeremy Salm DM3)? Plus, in a lot of cases, there's a huge gap between asking price and selling price. Someone may be asking $1500 for something, but more than willing to take $1100 for it, or they may be completely firm on their pricing.