Considering he claims to have this many accounts, I'm almost positive that if most of them have trained skills on them and aren't level 3's, then he gained them by putting out a keylogger for some kind of fake runescape bot or program. It would explain how he doesn't know how much is on each account, and how he has so many. This would mean that the accounts could potentially be recovered back, and that your dealing with hacked accounts which most of you probably don't care about but I think is pretty low. Anyways, happy bidding I guess...
he is probably like one of those youtube posters, where you can try to be runescape member for free, you just have to type in your acc name and password on www.blablarunescapefreemembers,something.org.com.wtfbbq. then he can see what they've typed, and he sells them.