I think the attraction is that they're small and quick and give you a chance to practice different stitches. And if you make them from something like Lily Sugar & Cream, they're really inexpensive.
As for being able to buy them cheap, I can go to the LL Bean website right now and I'm sure I can find nice sweaters on really good clearance. So why should I make any more sweaters when I can buy one at $20?
I think we can ALL answer that question!
:XX: :XX: :XX: :XX: :D