how much does Koynless tap to pay cost me ?

The fee structure for your Koynless account is very simple and transparent.
You pay 1 flat monthly fee per machine to Koynless to operate your telemetry data server.
Besides that your payment gateway provider (Mollie) may charge you a small fee per transaction.
There are no strangle contracts as you can cancel your account at any time.
You can set your own pricing per machine credit and even create tiered discount bundles so ultimately it is up to you how you operate your margins.

You can even lower your Mollie percentages by bundling credits for your players. For instance : when Mollie payment gateway charges you 0,20 per transaction and you charge 1,00 per machine credit to your players that would amount to a 20% fee, but if you allow players to buy 6 credits for 5,00 you only have a 4% fee. You can change all these payment settings in your Koynless account.