I agree a vintage singer or...what no one has suggested here, a 2010Q juki. At Raichert you can get one around $800 or so, and that is not too bad and it has a very large throat space. It is single stitch only, and no zig azg.
I myself have a 15-30 from my MIL, a recently acquired 15-91, and a recently acquired 301a. All these machines are in the process of being rehabilitated, so I have not sewn on them yet. I got these as I could not get a juki, no money for that for now.
For zig zags, I have a singe 1022 and that machine does the zig zags. There was one of those on ebay recently for $50.