It is a problem. I have bought AAAA Titleist NXT Tours from lostgolfballs.com over the last few years. While all the balls were NXT Tours, they ranged in years back to 2003 and 6 different versions.
I found out that the original NXT Tour was a 2 part ball, and had very different characteristics from the 2005, 2008, 2010, and 2012 versions. I noticed some balls played differently than others, but never considered there were different versions of the ball and instead blamed it on my swing. I have since gone through and sorted them all out, so I at least know what I'm hitting.
Originally Posted by robrey85
Yeah, that's probably my only gripe is that you can get a lot of all the same brand balls, for example E6, but they could be different years and I think different years have some changes and what not. I see what you're sayin' and I might just go that route eventually so I can support some local golf shops but for now I would rather go with what I can get on ebay or lostgolfballs.com