If Sniper Ghost Warrior Contracts generated the same gross revenue on the Epic Games Store, CI Games would keep approximately $9,099,866 - that's $1,946,571 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $1,104,527. 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 $7,143,075.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.