Trio#1: Constant f2.8 on all three but shorter and 3rd party lenses
Tokina 11-16 f2.8 Pro DX $600
Canon EF-S 17-55 f2.8 IS USM $1060
Sigma 50-150 f2.8 II EX DC HSM $750
Totalingto $2410 at B&H.
Trio#2 Slower but more reach ... and all Canon for $150 more
Canon EFS 10-22 f3.5-5.6 USM $770
Canon EF 24-105 f4L IS USM $1150
Canon EF 70-200 f4L USM $640
Totaling to $2560 at B&H.
All prices for USA models and without rebates ...
Which would you choose for a 50D user?