250 USD for Sr.Member? Seems a fake to me. Why would anyone sell their only account for such a cheap price? Maybe you have like dozens of them and not value it. Anyway, honest members will stay away from deals like that and you'll only attract scammers. You deserve that.
That actually sounds reasonable to me, although I don't exactly have my finger on the pulse of the account sales market. The reason why it'd cost so much for a Sr. Member account is that it now takes forever for someone--and usually an illiterate, spamming account farmer--to rank up that far. For most morons who sell accounts chronically, I don't think they'd even be able to nowadays without resorting to merit-dealing, and they'd risk getting tagged for that.