It is not so much the payment methods, but rather the types of transactions. In most cases, deposits will be free of charge. Usually, payment providers charge a merchant, or in our case — an online operator — when it comes to deposits.
With cashouts, the most expensive methods are bank transfers and wires. They charge either fixed sums or a percentage on top of the claimed win. E-wallets and crypto-wallets come with lower to no fees (depending on the casino’s policy), but if you decide to then cash the win out from an e-wallet to a card, fees are inevitable.