Heather,

I'm not Gregg, but here's the short answer to your question:

Typically, boots fail only after a significant number of miles and once "blown" not only lose lubricant, but take on dirt. That combination doesn't take very many miles, on top of the normal wear already a factor, to create a problem. Even though the CV joint is not "worn out", it must be removed in order to replace the boot and it is regarded as false economy to put the old one back in after going to considerable effort to remove it. You could have them relubricate the CV joint and reinstall it with a new boot and maybe you'd be OK - but maybe you'd be looking at replacement fairly soon. I think I'd shop around for a better price, but I think I'd go ahead and replace the shaft.

For what it's worth.