Well, the 70-200 f/4L will give you a solid telephoto for ~$600. That'll give you a superb quality replacement to your 75-300. This lens gives you the optics and build of $2000 lenses in a cheaper package. There's no IS (the IS version is $1000) but it's a great lens nevertheless.


The 85mm f/1.8 lens is sharper, longer, better built, and overall a better lens that the 50 f/1.8. It'll cost about $300.


Fast, sharp zooms cost more than $500. Sigma, Tamron and Tokina lenses are often 1/2 the price of their Canon counterparts, and sometimes are just as good. Beware of Sigma in particular because their quality control isn't all that great.


Good Luck!


brendan