I've searched far and wide for these sets for the better part of a year, and have managed to obtain two (which I love). one was through lots of luck, and the other was from lots of cash.
some of the sets are relatively less rare, others I've never seen a recent photo of
a few sets have popped up for sale around here and reddit, but they're mostly priced at $150+ USD
like Belfong said, one of the best ways would be to express your interests in the classifieds, and just wait
good luck