I was very blessed to have gotten a used one from ,my local dealer. It came services, with all the feet & extension table, and a year warranty all for $1,000, the lady traded it in for a bigger machine. I LOVE mine, it's easy to use ANYTHING you need to k ow about the 6600 you can find on the Internet / YouTube. I'd but the cheaper (if it comes from a reputable seller ) and go from there.
Your gonna love it!