The Bernina 930 is one of the best & most sought after none computer machines Bernina made. I have one. Bought it new in 1983. The 930 is a workhorse machine. The only part I ever had to have replaced was the feed dogs. I used my machine to sew heavy fabrics & wore the teeth off the feed dogs. This machine will sew any fabric, including saddle leather. It's an awesome machine. When I bought mine Bernina was giving a free sewing cabinet (with knee lift (free hands sewing foot lift) the machine. I still have mine set up in that cabinet.
Make sure the electric cord is there & works. Also the foot pedal. Some had heal down needle drop. Have the seller plug the machine in & do a test sew. If the owners manual is lost you can download it off Bernina's site. Mine also came with a accessories box & several feet. The box has a lift up lid. There should also be a hard plastic carrying case the machine came it as well. Knee lift leaver should be with the cabinet.