I haven't seen Winchester or Remington 22-250 brass for sale for quite awhile. I suspect the recent run on components for .223 and others has caused the manufacturers to produce components for some chamberings on a less frequent basis.
Winchester has been my favorite 22-250 brass, but mine came from 40 round varmint packs bought well before any of the ammo crazes. I have been less than impressed with the newer production Winchester .223 brass I have seen, which makes me wonder if their quality has slipped with other brass. I want more Winchester 22-250 brass, but I am a bit leery about their current quality standards.
Midway has Lapua brass on sale at a significant discount. Still not cheap, but probably good stuff, and it's available.
Another option is to look around for Prvi Partizan ammo. It is typically between $13 and $15 for a box of 20 and the brass is pretty good stuff.