There are very few treadle machines that have a lot of value. On the other hand, there are people who would love to have them and restore them. They don't usually pay a lot of money for them, though.
The ones that bring money are inlaid with mother of pearl and/or are particularly pretty or the ones that are rare. Most of the rare ones are from before 1900 and they don't look like sewing machines.
If yours might qualify for that rare or particularly pretty designation, post a photo and get an opinion. There are lots of people here with opinions.
bkay