I used to be in a Pony Club. I had them since I was 12-13 and im 18.
Ok, you've given us no information ... Titles? Authors? Circa? . If they're books that were bought new when you were 12 - 13 then they'll be worth no more than half their original purchase price unless they are part of a limited series collection.
If you go to a book drive for homes and Hospice and stuff you'll pick them up really cheap.
Its from the Pony Club. It has the logo. But yeah Ill see the authors names..