for the pillows, noa needs to be on the ground floor when they're in manufacturing in japan. making shit is expensive, especially custom stuff with lots of colors and intricate designs. if noa wanted 10,000 and japan wanted 10,000 then it drops the overall price a bit, compared to making two separate orders of 10,000.
so noa might have just missed the boat for those. same with the controllers and other cool stuff japan gets.
the cards are actually pretty nice, and probably cost nintendo about 5-7 bucks to make a whole deck each. depending on the quality of the posters (like if the zelda one has gold foil or something), they're probably more like 3-4 bucks each, tops. quantity matters too, and i don't know how popular club nintendo is. i'm just assuming low, so somewhere in the range of 6-10k for each platinum item. although nintendo probably gets their orders in july and then does the manufacturing in august and september, receives them in october, and ships in november.
anyway, the games cost them just the price of the game people might pay for, but it costs them extremely little to actually give away. it's nice that they are actual giveaways, but platinums should at least get a crack at one of them- or two if they don't choose a thing.