I know they're not glamorous, but I picked up a cheapo chinese air rifle from a feed store for $20. It shoots right around 900f/s.

BTW - I recently decided to stop using my pellet rifle and bought some CCI CB Caps. They come in Long or Short, but have the same ballistics. They run 727f/s & 34 ftlbs out of the barrel. The 29gr lead slug is more than enough for the local squirrels and starlings, they're about as quiet as a pellet rifle, they won't go through a 2x4, and the trajectory is about the same as the LR out to 30 or 40 yds, so I don't have to adjust my scope at all. Also, the ammo is right around $0.06 per round from wally world.