If a case isn't that important to you they easily fit into one of the sterlite file folder box. Most times they go for a lot cheaper without the case. Just make sure you get the bobbin holder and the foot pedal.
But like the other's said bid at the last minute. I use bidnip. You buy bids but they are really cheap. I've forgotten how much since my only purchase was 4 years ago and still have some left. You don't pay if you don't win. Bidnip has helped me win a ton of times.