Canon Lens

ok, i know that is a pretty broad question, but let me elaborate.

i shoot a T1i. here are my current lenses:

18-55 IS
28-135 IS USM
55-250 IS
50mm 1.8
60mm 2.8 macro (my fav lens)

not in love with the 28-135 range. i like the lens itself a lot, but i need a little more on the wide end. i hardly ever use the 55-250, but i guess it is good to have.

what i would like to do is possibly consolidate. i might be willing to sell/trade the 28-135 and the 18-55 for something like the sigma 17-70 f/2.8.

any thoughts? i am looking to spend maybe 300-400 at the most. anyone have anything available?