MageKnight did that for a while. I was able amass a sizable collection by trading my painted figures. l would love it if Heroclix would do that as well. The unpainted packs were also much cheaper. Sometimes you can snag unpainted Star Wars or D&D plastic figures off of ebay. Folks in China selling off the unpainted rejects, or just snagging them when no one is looking.
Yeah, that is true at times...although it pains me to pay a more premium price for a painted mini, just to turn around and strip it.
It seems to me that there is nothing wrong with prepainted minis, but why can't those companies also produce the same mini, just without the paint? A limited run even...I can't see how that would cost anymore (although maybe additional packaging..)
I don't know, it just seems that the there should be a happy medium for both ready to play gamers, and painters.