Your best bet would be to give them a call. They can tell you what they are looking for and the best time to go down to the store. The staff is very helpful and knowledgeable. If they aren't interested in purchasing your books, I'm sure that they can point you in the right direction.
WhatJenna said. If they don't got it that's a step.
It depends on the value and rarity of the comics, and the condition of it. They have a wide selection, huge even, so it would be hard for you to show them something they wouldn't have a copy of.
Thanks! Your answer is awaiting moderation.