Check it out for sure. At that price I would get it as a second machine. If the BSR is there it's $1000.00. If it comes with embroidery, that's another $1000.00. You do need a lap top to use the embroidery unit I think. Most of the Bernina feet are about $50.00 each so see how many of those come with it. Is she throwing in the accesory case/instruction book? It usually comes with a carrying case too.
Bring samples of different types of fabric to check out the sewing. Silky, cotton, fleece, quilt sandwich etc. to see how it sews. Lower the feed dogs down to see if they work. (button that you push in on right hand end of machine)Check to see if you have an authorized Bernina dealer in your area for repairs/oiling. It has an indicater that comes on when it needs to be serviced. The Bernina serviceman can tell you how much sewing has been done on it if you buy it. Pay with a credit card so you can stop payment if you have any trouble?