Now you've gone and done it. (Kurt will be by shortly to remind us that "Gresham's Law" is a silly special case of a general and trivially obvious economic principle.)
The nonsensical face value amounts are to hopefully prevent people from spending them. Otherwise you end up like Canada whose lost millions on the $20 for $20 coins because they speculated silver would never go down or didn't think ahead in the chase for quick easy revenue. Although if I was the Canadian mint I'd just release the millions of returned coins they've received into circulation as true legal tender at this point and avoid having to take any more returns if people could just circulate them anywhere.