Since there is no central bank controlling the cryptocurrencies, it's important to understand that each provider chooses its own rate (and often won't tell you about it!). However, to help keep things clear, services like TradeBlock XBX lists an average rate based on the known providers. Coinmama's rate is based on the XBX Index, plus a 5.90% fee.
Credit card processing fees
For credit/debit card transactions, there is an additional 5.00% processing fee. This fee will be added after choosing your method of payment.
Tip: If you want to make sure there is coverage on your card, take the final amount you want to spend and divide it by 1.05 (so if you have 1000 USD to spend, 1000 / 1.05 = 952). This is the amount you can spend when choosing how much cryptocurrency to buy.
Bank transfer fees
For SEPA bank transfers, there is an additional 0.00% processing fee, however, your bank may decide to charge you for creating the bank transfer. Consult with them prior to creating an order.
For SWIFT bank transfers, there is an additional processing fee of 20 GBP on orders below 1000 USD. There is an additional 0.00% processing fee on orders of 1000 USD and above. Note that your bank may charge a separate fee for creating the bank transfer. Consult with them prior to creating an order.