I saw 2 old machines for sale at a shop in Port Williams today. There was a Featherweight 221 and an electric Singer, drop in bobbin. The 221 was in good shape and $275. That seems about right. The Singer was in excellent shape and $40. That seemed to be a steal. Both came with attachments. There was a third Singer, in very sad shape, for $25. It had a shuttle but was electric and portable.
I am currently piecing a quilt top on my Singer treadle. I love the stitch quality of these old machines. Vintage machines sound and feel so solid and hard working. If you want a great straight stitch on woven fabric, use a vintage machine. Everyone should have one and use it on a regular basis. It would be a purchase you will never regret!