Game citadel is the only one in the immediate area. But Briar Patch has a very small selection as well. And Bull Moose and Books a Million have a medium sized section. Also Target/Walmart occasionally have some good ones.

You’ll need to drive to Belfast or Augusta for the next closest dedicated boardgame store other than Game Citadel.

If you are on Facebook, you can join the Bangor Area Gamers Guild-BAGG group. They have boardgame meetups and folks sometimes sell their used games there. Also, there’s a gaming convention held in Bangor most Januaries called Snow Con.