I have shot Sony products for the last 5 years, first an A-380 then i boght the 580, which was a tremendous improvement, but i recently had the opportunity to purchase a Canon 7D and some gear at an outrageous price which I did. Being that most of the shooting I do is sports, Football, Soccer etc, I could not believe the differance once again between the 580 and the 7D. Your problem with blurry images at low light could be more from the settings you start off with that the camera itself, try adjusting your ISO factor and shooting from an aperture mode rather than full Auto. Whatever brand you buy take the time to understand the operation of the body, read some websites and dont be afraid to ask questions. You will see a big differance in the quality of your shots. Rather than using a tripod I use mainly a monopod, they are not as cumbersome and will hold the shot steady. If you are looking for a used camera, I have stayed away from craigslist, I have been jipped once off of sellers from there and that was once enough. I have bought much equipment from a site called KEH, and had some that Ive had to send back without any hassle from them. Many Camera stores will also rent you a lens for events that require longer glass, you can always see if thats the right lens for the job needed, and as one earlier post said about the quality of glass, the Lens is as or more improtant than the body itself. have fun, photography is a hobby that can easily consume you, kinda like chainsaws.
