Like what? Bear in mind, Valve makes profit on the first unit sold, while the dev doesn't see any profit on a $5M budget game until it sells over $7M.
I'm in the US. The transaction fee is about 2% on the credit card. I'm aware that most transactions in Asia may cost a lot more. I thought their 20% cut was after the first $50M? That royalty change btw came within days of EGS launching with their 12%, which suggests it was a direct response.
The original royalty change came before Epic announced EGS though.