Why do Amazon sellers do this?

Every time before a “huge sale” I see a bunch of stuff I’ve saved in my cart, up their prices then lower back to “original price” and call it a sale?

For example: 4 days ago, game was $59.99, price goes up to $73.95 2 days ago, sale starts, now it’s $59.99 20% off!!!!

How’s this allowed?? It’s so scummy