I'm curious why you wouldn't just buy a small SSD (i.e. 40GB) and put it in the mini yourself?
I don't know of anyone putting that forth as the low cost solution (nor is that sort of change out easy for someone who's really terrified to break their $700 computer and not used to fiddling with that stuff).
ifixit.com seems to indicate otherwise: http://www.ifixit.com/Guide/Repair/Installing-Mac-mini-Model...