$25 is not too much for a T&S in good condition. I often feel it's equally important it goes to someone who care and appreciate the machine, than what it sells for. I think it's reputation has a lot to do with setting it up correctly, and maybe some of the models had a few issues, but mostly it was about getting to know how the machine worked. The fancy bobbin functions in them was state of the art at the time.
Congratulations on your model 66, it was at the time Singers top model, with the newly developed drop in bobbin case. Some even claim it was Singers first machine who made perfect stitch, it's on the arguable side though :- )
Keep on oiling it often the next few weeks. It takes a bit of time to flush out all old dried up oil and grime and replace it with new fresh. It will make a difference later on.
Best of luck with your new machine
Mickey