Maine Military isn't bad. Friendly staff and the owner seems like a good guy. They have some decent deals on alot of surplus stuff. When they first opened their firearm prices were very fair, but in the past year or two the prices have gone up on firearms and ammo alike. They offer bottom dollar on trades so I wouldn't bother trading there. Occasionally you can catch a good deal on a sale they have. Last time I was there they didn't have the Vector in stock. You can call and see if they can order it, however.
Other than that I try to get there once or twice a month just to look. I have bought alot of hunting stuff there. They are located on Wilson Street in brewer. Not a red barn type building. It's just before the I-395 exit, on Wilson square, can't miss it.
IM me if you have any additional questions.