The Singer 111W is the basic compound walking foot sewing machine every other sewing machine company copied. There are at least 15 industrial sewing machines that are almost exact copies of the Singer 111W. If you find one that is in good working order for $300, you have a huge bargain, assuming that you get the table and motor and bobbin winder along with the sewing machine head. If you don't get the table and motor and bobbin winder, and if the machine is not in good working order, you can pay $700 or more to put it in good working order, depending on what's wrong with it. That would bring you to the point of being the same price as a brand new machine. This leaves you with the dilemma of buying something that you have no idea of whether or not it is a money pit. It may not be a money pit, but unless you are a sewing machine mechanic, or close enough to the seller to have it checked out by a professional, how would you know? In other words......if this machine is in Boston, and you live in L.A., PASS.
No one lives forever, the trick is creating something that will.