If Sands of Salzaar generated the same gross revenue on the Epic Games Store, 汉家松鼠Han-Squirrel Studio would keep approximately $7,457,640 - that's $1,620,881 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $880,587. Epic charges 0% on the first $1 million in annual per-app revenue and then 12% on the remaining amount. On GOG (30% cut), the developer would earn approximately $5,836,759.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.