You may want to spend about 250 for a very good brand new one instead of purchasing a used one. You could be buying someone elses problems-who knows? I got the one off Nancys Notions for 249, came with notions package. I love it, it does everything I need it to do. Brand new, has a warranty too. This is just my opinion.
I will admit, I am a BabyLock fan! I have an Ellagante I would never part with. Only because I cannot afford to upgrade. If you are after the Babylock name, a GF says this serger is a good machine. $400 seems very reasonable. Would the warranty be transferrable on this?