I found both of mine advertised on craigslist. One of them had been in the attic for many years and needed servicing (which I did myself). The other was ready to go, had a receipt from being serviced 4 months prior. There are usually some advertised in my area, but I've noticed that they are overpriced, asking $400-600 when the going price is more $250-350 these days. #1 thing to check is the bobbin case - if it is missing it would be $50 or more to replace with an original. Also look for ones that have the case and attachments included.