Zoely, I am not sure if anyone else in the world would agree with me, but I love my old Singer 15-30. It isn't quite antique yet, but it is a treadle.
Anyway it is just a suggestion. You could get an electric (or treadle, lol) Singer '50s or earlier, especially any 15 model for between 25$ and 100$. Imo it is way better than any of the 400$ and below modern plastic machines I've used.
Actuallu I saw a lot of industrials for reasonable prices while searching for my newer 15. (eBay and craigslist.)