My ex-wife has had a cheap ebay one since February. She's happy with it so far. I advised her to get a George Knight but it's better that she got the cheap one, she's not selling a lot of tee-shirts.
Be aware that there's no support. If it breaks there's no source for parts. If you can't fix it, it's a paperweight. If you are testing the waters it would be fine.
If you've got your sales channel set up, if you're going to do 100 shirts a day, if you're a great designer with a ton of great ideas, go for one of the name brands - Hix or George Knight.
If not, get the one from ebay. It'll do the job well enough. Better to have a $200 dollar item sitting in the corner gathering dust than a $1200 one.