One thing I was thinking of was perhaps these weren't made for the U.S., but to be sold to collectors in other markets. If, like you say, they can be made for 3 cents each then sold overseas to casual collectors who may not be aware of how the genuine coin looks for one or two dollars each, then it may be worth it to pump out a few thousand of these. Perhaps a few of them just happened to make their way over here and got put into circulation as an afterthought.
I never met a man I didn't like - Will Rogers
I never met a half dollar I didn't like - DeputyMax