On the EU e-shop (seems to be similar for the US one) Breath of the Wild has regular 30% discounts starting about one year after release. It's been 6 years, it never went lower, and probably never will.
Same for Mario Kart 8 Deluxe. It's been almost 10 years since the original release of Mario Kart 8, and eshop sales never go under 30%.
Nintendo is known for keeping their games mostly full price. The only games that get big sales are the ones that didn't perform as well as they wanted, and even that is becoming rare.
