@TTJ, @casperweb, thanks for the input, by 70-300vr you guys mean the f4.5-5.6 lens?
@sevencrossing, @tcole, thank you for the prompt response. I see your point of lenses holding the value.
I will have to capture some of the indoor events, with less lighting and people moving around fast.
you need to let us know about the event you will be covering,
how far you will be form your subjects,
will you be allowed to use flash,
how high is the ceiling
if no flash, can you use a tripod or monopod.
lots of questions, but the answers usually dictate what equipment you carry to a shoot.
as to the 70-300 being blurry, you have a camera that will allow you to crank up the ISO to keep your shutter speed up, within reason of course.
as TTJ said, there is no magic bullet lens, that is why most of us end up with a collection.