I bought a 221 on Ebay and took it to the local machine shop where he fine tuned it, and showed me how to use all the accessories. She isn't perfect (missing some paint) but she purrs. He told me the motor was in excellent shape. He also gave me this advice:
Never turn the fly wheel backward, it messes up the bobbin. To make the machine go backward, put the lever up to the top.
Some things that cost a little more on the 221 are the graduated throat plate (nice to have) and he told me that the color of the screws and screw driver (black are worth a little more) as they are more rare. Those things don't make a difference to me. I just have mine for travel, and I love it.