If you wanna talk massive money sink and a cash cow from Nintendo, all I need to mention is Animal Crossing amiibo cards + figures. They were produced for such a short time that the prices of the cards skyrocketed and they were being scalped. There actually became a market for people making their own fanmade cards because of this. The 50 cards they released in the Welcome Amiibo update acted as a DLC, as each card brought along a new villager you could move into your town, as well as new furniture and items found ONLY in those cards, unless of course, you were a part of the forums and could trade for the items. But, short of that, the items were hard to come by, and I believe it was nearing at least a hundred items locked behind a pretty piece of cardboard.

I am ashamed to admit I spent 150 dollars on a complete set of the 50 WA cards. I also bought each and every one of the Animal Crossing amiibo figures, because they also gave items in-game.

And don't even get me started on the fact that certain other characters could be gotten as well, most notably, Link, Epona, the two Splatoon girls, and a couple of others. There was also a rare set of Sanrio cards in the same set as the Welcome Amiibo cards, and they started off as a Japanese exclusive, so you were looking at 60+ dollars for a complete set of 6. They recently got a re-release all over, but scalpers once again bought the cards, and off went the prices.

Soooo... good job, Nintendo.