I'm currently using a 30D w/ grip and a Sigma 100-300mm f/4 for Little League and HS baseball. I've got a budget of about $800, and I'm considering either upgrading my 30D to the 1DmkII for higher fps and faster AF, or buying a used 70-200mm f/2.8 for better low-light performance and background separation. Which do you choose?






