OK I am lusting after your 750 and have 2 FWs that I would be happy to trade you. LOL I am seriously looking at that machine after I sell my 730.
I would vote for looking on craigs list in your area so that you can test it out. Also let all of your sewing buddies know that you are thinking about one and your price range. Also print out some example of the face plate you are looking for. You can also tell all of your other friends and relatives, it is amazing what someone might run across. My husband found mine in a yard sale (perfect condition even the case) for $30 and this was before I was even quilting, he just thought it looked cute!