Hi Itsmesilly,

Sounds like a fun trip, I'd love to do that!
Most pawn shops, in my experience, have mostly cheaper guitars but you can find gems once in a while. I don't think most pawn shops are out to get you but they will try to get the MOST that they can for a guitar or whatever. And now with the internet it's easy for anyone to find out what the max something is worth, inclucing yourself. Since you have internet, I would use that to look up a guitar on ebay/internet to get a ballpark figure on what they go for. If a pawn shop has a gem, they're probably gonna know it.
I would guess that your best bet would be finding a ma and pa store somewhere with a little down home charm and maybe they're not all about the bucks, sounds like you might be in that kinda neighborhood.
Happy Hunting, have fun!