Dear Kddani,
I am probably going to repeat what others have suggested but this is what I would do if I were you:
I would also feel compelled to buy the badge not of my org. First, I think I would try to contact any of the local chapters to see if they wanted to buy it for the price I bought it at.
Second, I would try the local alum. Third, I would try the HQ of the org. I know most HQ's dont buy back badges but I think a few set aside a part of the budget for badge recovery.
Third, I would offer it here for non profit. Assuming John has no problem with it.
I would NEVER sell something on ebay though!!!! You can never be sure who it is who is buying them, there are liars everywhere!!
Just my thoughts!
Good luck,
Oh and if you do see any Alpha Gam badges let me know!