.Is the Machine Threaded? Is there a Stiched Sample? Light On?   Foot Controller Plugged In? Does the Seller know how to Operate the Machine? Is there a Book?  These are NOT the most user friendly machines in the world. The Famous Little Featherweight 221 has a very unconventional threading system. The needle can be put in backwards by mistake, the needle is threaded inside out and it can be confusing. Try to buy a machine with an instruction book.  If the seller says that they don't know much about sewing and that the needle goes up and down..beware...that does not mean that the machine sews,  it means the needle just goes up and down..  Look to see if there is a bobbin case, preferably with a threaded bobbin inside it.  If the original case is missing, the buyer will have to use a replacement part from a foreign country.  The Singer Company does not make any more original replacement parts for our Featherweights. These little machines really work their best with as many original parts as possible, including the belt unless it is truly worn and tattered.  Look for a nice clean finish on the machine, this may tell you how the machine was treated.  Watch for bubbling paint near the bottom of the machine..it  means that the machine sat in a damp basement for months or years. Ask about mildew and musty odors.  Beware of machines with adhesive tape on the bed that was once used as a seam guide. Masking tape is nearly impossible to remove and you may remove the finish with the old tape.  Try to see if there ever was a makeshift pin cushion or pin collar attached to the upper arm of the machine above the needle bar which will have left hundreds of small pin scratches that just ruins the finish.  A clean carrying case with working latches is a real plus but it won't make the machine sew any better.  The keys for the cases are a plus, and nice to have.  Examine the pictures carefully.  Try to compare the machine to other featherweights.  If you have a friend who has one that she loves and uses, study it carefully and remember what an operating Featherweight should look like, and what the foot controller and the wiring is supposed to look like. Week after week, people walk into my shop with sad faces with Featherweights, that were bought  because the price seemed.....Too Good To Be True...and they can't make them sew because of missing parts, damage to the hook area, lights with broken sockets, bent stitch length levers, frozen tension assemblies, bobbin winders that are frozen and will not spin.  If you just try to ignore all the extra feet or old patterns, or old non-functioning stuff that sometimes blur your vision and concentrate on finding a Featherweight that will SEW for you in your home, in your sewing and quilting classes, and just be fun.  Return policies are nice, but you will be on the hook for $60 in shipping back and forth, and you still will not have a functioning sewing machine.