Well, I suppose the more diplomatic (lol) way of saying things is that speaking in general, buying an accordion from a pawn shop is likely one of the worst places to get one, HOWEVER, this is your first accordion, you are just starting out, and it's not the end of the world. That said, there are some things that you could have done to protect yourself from making a purchase that would potentially cost you more in repairs than the actual value of the accordion itself.
All that said, enthusiasm and a little luck can trump most of the small issues, time, experience, a little grim determination and money takes care of all the rest.
As requested, post a picture of your accordion here, there are many people that will be willing to offer an estimate of the value. The odds are slightly against that, but who knows, maybe you got the deal of the century.
By the way, welcome to the forum!