I am VERY picky about the BBs I use.
Jon and I both seem to have the same taste in BBs, and the same concerns about shattering or chipping BBs. we are constantly testing even brands we know are good, cause recently, the Airsoft elites were shattering on impact , where as before they were breaking on the seam... if they broke at all.
ANY .12 in anyting over 200 FPs, is going to break and shatter. I dunno why they even make the .12s to be honest.
don't buy BBs from Walmart, Academy, or other "sporting goods" stores... they don't carry "good enough" brands.
Saving a few bucks, on quality ammo... is not a good thing. Not only are the "cheaper" grade BBs bad for your AEG, they aren't polished enough for good accuracy, and of course... most of em shatter or chip when striking hard surfaces.
Placing all the responsibility on your OPFOR, is flat out the wrong way of thinking... in the name of saving a buck or two, at least.
The cost comparison is nominal at best... 5,000 cheap grade bbs, is not THAT much cheaper than nice 4,000 count bags of decent grade bbs.
My recommendation, buy your BBs from Sogos. Jon doesn't carry crap BBs. Prices are affordable as well.