Yeah, it's the kind of thing where, if it were like, a Sythe mod's account, or someone that were EXTREMELY safe, I could see them getting $100 for it or something.
The problem is, there's no value in the Runescape account itself other than its login name, so whomever bought it would have to put a ton of work into the account, and never have much safety in it not being recovered.
Sorry OP