I got 28 awg kynar on the bay. They come in 100 foot spools for around ten bucks. I bought 2, and they're different from one another. The one I like a lot more has a note on it saying it's Brand Rex.
Update, the one I like says the insulation material is kynar, the one I don't like as much says the insulation material is Polyvinylidene Fluoride (PVDF). I really don't understand those names, but the kynar insulation seems to be higher quality.