Makes me nervous to buy big items on line, especially used. I bought a used Babylock Ellageo, but I bought it from a dealer. If you have any dealers in your area you might see if they have any used machines. Even with used you can get a little warranty sometimes, and lessons..also maybe craig's list for your area...at least then you could go and look at it and have them let you try sewing with it and maybe stitch out a design for you so that you knew it worked well. Or post a "machine wanted" type add in your local newspaper freebie adds. Just some ideas.
Good luck with your decision