you can find Brother's and Singer's, but even they are going to be a bit more than that. Some of the lower end machines only have a 4" x 4" embroidery area, others 5" X 7". I haven't seen any new ones for under $600 but then again I haven't looked in a while.
I have a Singer Futura CE200 and other than wishing for a larger hoop, it is a nice little machine. The newer model is a CE250. My machine 3 yrs ago was $600.