I own a small photography business which started as a hobby but has begun to pick up clients recently. I have very little capital, so I chose to buy a Canon T2i a couple of years ago instead of higher priced options, choosing instead to spend some decent money on a 24-70mm f/2.8 lens.
This setup has been working well so far, but as I get more work, I've become increasingly frustrated with the quality of many of the images I've been producing-- they're not as sharp as I'd like. I want to upgrade to another model with sharper focus.
My budget is between $500-700, which puts me in the range of a 1Dmkiii, 5DMki, 50D, or 60D. I need help deciding what to go for with the end goal of sharper focus than the t2i. Any advice?