People can buy what ever they want, just as long as they don't try to resell it as an original, or try to convince others that it is better to buy replica toys instead of legit ones.
People who have limited funds, or affections with certain rare toys, sometimes buy a counterfeit toy, as a substitue until they can afford the real thing.

And I wouldn't have any problem with someone using a counterfeit toy for customising, so that it doesn't take a real (and sometimes rare) toy out of circulation.