I just got a basic but cheap model at Walmart. It's a regular size "beginner" sewing machine and I think I got for like $60 or something a couple of years ago. I opted for a "real" sewing machine instead of one of those mini ones so I could also do regular sewing projects too. I'd read alot of bad reviews on most of the mini's back then, too, but I hear that now Janome (I think it is) a good mini one, if that's the size you're looking for. Maybe someone else on here has more advice on those.
I opt for a real machine as well. I have a Singer that I use for sewing and I just change out my needle when I sew on my cards. I did have for a while a second machine I purchase at a garage sale for my cards but it finially died this year.