I bought a couple crates of ammo 2 years back and it all came on strippers and in bandoleers. As I would shoot them, I would take the empty strippers and throw them into one of my gunshow cases. I felt guilty charging a buck for them, but guys couldn't seem to get them fast enough. I ran out at one show, and guys were so desperate for them that they would buy a stripper full of dummy rounds from me for $12 just to get the clip.
Sheer madness. Market price these days would seem to be $2. And thats cheap, since a spare mag here in Canada goes for between $35-50.
Of course, the strippers are useless to me other than to keep my ammo organised: I shoot the sniper rifle almost exclusively, and the strippers can't be used unless you want to take off the scope. As a result, I end up carrying a sig satchel full of loaded mags.