I have a fairly basic Brother that I love. I don't remember just how much it cost (about $300), but I did some research and ended up negotiating. (Yes, even on a low end that is possible). It doesn't mind being carted to the quilt classes, and it does a better blanket stitch than my higher end Pfaff.
I wonder what is wrong with your machine, since you just had it serviced. It is possible that you have the bobbin in incorrectly like a previous quilter postet. Can you take it back to the service place to have the tech walk you through proper setup or have an experienced sewer in your realm check it out. Sometimes the older machines are better work horses than the new ones, and for quilting you need to be able to sew a consistent 1/4" seam (straight stitch).
If you end up getting a new one, make sure you test drive it and put it through its paces.
Good hunting.