Theres 2 milestones to unlock the ? items in the salmom run shop you need to spend copper, silver and gols scales to unlock those i think the first 1 is at 100 copper and 10 silver and the 2nd milestone is at 350 copper 40 silver and 4 gold
Of your talking about newer items thats when the season is over and it adds new stuff after the content update

As the title says, I was wondering if the shop in salmon run where you can buy things with scales will ever change? Will it always be the same things in it forever or will everything be replaced with new stuff to buy every once in a while?

Does the salmon run shop ever change?