Games that are actually made by Nintendo tend to be expensive and are rarely discounted anyway, at least on the Nintendo store. The online store also isn’t competitive whereas the physical shops tend to try to beat each other on price. If you can you need to try and find games that give you a download code that you can buy from shops, online stores, etc.
There’s an iPhone app I use called NT Deals. It watches the Nintendo Store and it will show you details about games like the lowest price it’s ever been and you can set an alert so if it goes on sale or the price drops it’ll let you know. I’m a PC gamer normally and I refuse to buy games at full price. It took about nine months before I could buy Zelda BotW because it took so long to go on sale even years after it was released.