I find more than I loose, and I find some good ones and have decided that I don't need to keep the cheap balls.
I normally give the ones I don't want to the local course to use for the youth golf program.
I normally play the ProV's I find as well as the NXT's, Cally higher-end balls and some of the higher end TM balls.
The rest are donated.
As for buying, I bought 4 dozen Kirkland, but have only used a few so far, I got some Callaway balls for Christmas, but have not broken into those yet. I have more new balls than ever, but still have plenty of super clean ProV's as well.