I no most people like to sell their account and some maybe disappointed they do not get much. That would be because the skills people want you dont got. What I am saying is sites that buy your account base it on how hogh certain skills are.

1. Dung if you have that maxed you accs value is pretty high just because of it
Herb, Farming, and Prayer are also good to get up because you pretty much need wealth to get them up.

Agility is also another good 1 because everyone hates doing it. So basically for the people who just go for woodcutting, fishing, cooking, and firemaking i would not work on that unless u need money or if your f2p.