Might be a 15-91 or 201 - either would be good for quilt piecing. Hard to tell from pic exactly, but for the price, you cannot go wrong. They sell for at least twice that without a cabinet on ebay. Might ask seller to email you the serial number (I'd explain to them it is on front right near bottom of machine - they may not know where to look).
Once you have the serial number you can then identify the year of manufacture & model (15-91, 201, etc) at this site:
http://www.singerco.com/support/singer_numbers.html
Good luck with the decision - let us know how it turns out.