When I was buying a machine, I looked for a good local dealer. I wanted to be able to get free classes and have someone to service my machine and honor the warranty. I think the first thing to do is visit different dealer and machines if you can to see what you like and can afford.
I also went with a list of must haves....lower the feed dogs for FMQ, largest harp space I could get for machine quilting, a good buttonhole stitch for machine appliqué, adjustable pressure on the foot, needle up and needle down feature, good lighting were a few of mine. Good luck!