It is a Japanese machine based on the popular Singer 15, probably made in the mid-to-late 50s. I'd usually say that $100 is a bit high, but this particular machine has some interesting and unusual features and I think that it's probably priced about right. It should sew very well for you. I use a Japanese 15 clone for free-motion quilting and learned to sew on a Singer 15-91. They are excellent machines.

Annie