I have the Brother PQ1500s which is similar to the Juki that I think you are talking about. I love my PQ - I got mine used for $350 including shipping. It quilts like a dream and I've done some pretty big quilts on it, I use it as a sit down quilter. Reviews from Folks who have the Juki (98, 2001, 2010 are the models like the Brother PQ1500) indicate that they are also very happy using them as sit down quilters. I think they are an excellent option within your budget.
Rob