Release keep an eye on RockBottomGolf. They always have some great deals on balls. I've not bought any of their used, but when they get their hands on new logo balls, they are really cheap, and brands vary. I bought around 6-8 doz. last winter, the Callaway Warbird, and still have plenty for next season. I'll piss around and try a couple other brands/models along the way, but I never go over $20/doz.. Just no sense for my game to spend any more than that.
When Titleist started changing their balls every year, I got away from them. Used to play a lot of the NXT, which I also thought to be better than the ProV1. Now, they seem too hard. Could be old age, or could be their changes, but I stay away now.