And if there are any places for buying recycled house wiring and such, like Stardust Building Supplies here in the Phoenix AZ area does, you can often get it really cheap.
Sometimes you can find good stuff salvaged, too, from discard piles at places that do networking or server setups:
Sorry I don't have a pic of the bare wire, but it's nice stranded copper, not super fine but flexible enough. Ain't gonna fit this cable thru any axle I've seen, though.
Well, there is this pic:
but all you can see is how thick the wire is.
I don't have any good pics of it, but you can also get good teflon wire in usable lengths from aircraft wiring harnesses and test equipment harnesses at various elecronics scrapyards. Sometimes for nearly nothing, depending on how good a friend you can make there, or how interested you can get them in your projects (or how interested you can be in THEIR projects!).