[wdfifteen]

This is from my wife, who has a Featherweight she uses every day, (plus a Bernina, an Elna, a Juki, a spare Featherweight, and a 12 foot Innova long arm quilting machine).
Singer Feather Weight will only do straight stitches on fairly thin fabric. Eighty year old Featherweights cost a lot because what they do, they do VERY well. But for your needs a new Singer Heavy Duty would cost less and do more along the lines of what you say you need. The prices are all over the map depending on features. A basic one that will do half a dozen different stitches is less than $200. You can get them at Walmart.
If you buy an old Featherweight you will have to have it tuned up at a minimum, so plan on paying $50 to $100 over the purchase price and finding a place that will tune it up.