I worked in a sewing machine dealership years ago and bought my Bernina 1230 at that time. I would not recommend a Bernette; they are just not powerful and are not made well.
Many people here have mentioned that the Janome Gem is a great portable machine for taking to classes.
Have you considered buying a used portable? Check all the dealerships around you. Some of the older small portable machines are really delightful, and they shouldn't cost $250. I found a cute little compact 1970's Singer for $25 in a thrift shop -- weighs about 12 pounds and comes enclosed in its own case that holds the foot pedal, etc.; however, you don't run across machines like this very often in thrift shops.