Do you mean mint -- as in never used? Or mint as in excellent condition? There is a difference.

By the way, I would be cautious about using a camera that has never been used. For a body, I would expect you to pay at least $1,000 from a dealer, possibly a bit less through private sale. For that kind of money, it's probably best to buy through a reputable source, or at least from someone that is trusted -- whether it be eBay, an Internet forum or someone at work