Been there, done that. I recently paid $40.00 for a Singer 600, because I wanted a metal geared slant stitch. Then I find out they are really crappy machines and mine needs lots of work. However, I paid $35.00 for an Elgin a few months ago that runs so smoothly that it literally hums. It doesn't need anything.
You win some and you lose some.
Welcome to the world of a sewing machine lover.
bkay