Agree with both of the above. A lot of new stuff on Gunbroker is over priced when compared to other internet sites that sell new. I have seen some good deals on used there though. Build a relationship with a local gun shop and many of them will cut deals on special orders for you.
If you first click on the advanced search option on Gunbroker, you can then click on the tab for completed items. This allows you to search for items that actually sold which gives you a much better idea of real market prices instead of just overblown asking prices.