I feel the need to point out, a lawsuit claim isn’t proof. I can sue you for being a goblin, for example.

They are suing, making a claim, and presenting their side of the situation as their proof. You need to keep in mind there’s a non zero chance they have omitted inconvenient facts (to an extent) and misinterpreted information to their benefit.

Anecdotally, I’ve seen many, many, many games on storefronts other than steam that have a sale price lower than steam.