They're stuck with it. It's usually some crappy Brad Pitt avatar or something haha. Theymos has stated he will remove them but wont change them. Think one guy selling accounts specified what avatar they had though so you could pick before you purchased.
Yeah that's what i thought, so quite why people would pay money for newbie account with an unknown avitar seems a little silly me, but perhaps i'm missing something.
Thanks for the reply though Hilariousandco
Cheers
Mark