>>5640450Hiya, don't know if you're still there. Sadly these gashapon are very rare and usually skyrocket when they appears. Finding them won't be easy, finding them at a good price will really NOT be easy. If you're familiar to it, try stalking YahooJapan a lot.
As for other Mystery Dungeon things, there is pic related, some plushies (not common either) and some phone straps.