I created a free calculator that compares estimated Envato and WPBay earnings using your own product price, monthly sales, buyer fee, withholding tax, VAT and customer location.
For example, with a $59 product and a $5 Envato buyer fee, the author receives $27 per sale on Envato before withholding tax - and this can go even lower if the customer is from the US, as the US withholding tax will be also applied in Envato’s case. On WPBay, the same $59 sale generates $41.30 at the starting 30% commission tier and $51.92 on the final 12% commission tier.
You can try it here: Envato vs WPBay Earnings Calculator - WPBay
Let me know if the calculation matches your current Envato earnings or if anything should be adjusted.