Sigma 70-200 f/2.8 HSM Macro is going for $800 new. Not too bad compares to Canon 70-200 f4L. Definitely a possible choice. Fast AF, F/2.8 plus some 1:3.5 macro capability.
Still, I don't consider either a budget lens. For outdoor/non-action shot, 55-250mm IS simply can't be beat for $200 used. I have been trying to justify an upgrade from 55-250mm, but it's very difficult to find a "value" alternative.
Who buys lenses new?
I buy bodies new. Lenses (all of mine) are used. Saved a huge chunck of change that way