I'm a hobbyist/collector who also restores sewing machines.
Be assured that I do not "flip" them. Even if I did, the profit margin for my time repairing and sourcing and paying for parts for restoration would be negligible, if any; for the prices listed for vintage sewing machines on craigslist, most people nowadays can get a new sewing machine with electronics and other automatic features (threading a needle is never really gets "easy;" it just gets less difficult with time).
My niche is early 20th century to about 1968 with or without cabinets and cases. I attached samples representative of the unwanted sewing machines which I have picked up and sew with on a rotating basis.
I'm beginning to learn about treadle machines, which will take me a few more weeks to master servicing them.
I'm open to any condition, most of the sewing machines others have given me have been in really bad shape. So far, I have restored 100% of them.
I can arrange an on-site or curbside pick-up of your unwanted sewing machine.