*Update*
Went and got it a little while ago! The seller was really cool. I forgot to ask why so cheap but its mite free doesn't appear to have a ri and is active and curious! She told me she got it in January (probably from a pet shop type setting which would explain the lack of knowledge on age/gender I think)
The pics didn't do this pretty baby any justice. Way prettier in person. She also gave me the 30gallon set up for $20.
As far as the transaction went she was a great seller polite and never tried to push me into the buy or rush my decision. My guess is she was just a pet owner who needed the space back.