This is Moira from the Social Care team at Shopify. Thanks for posting, and a very warm welcome to the Community!
Currently, it is not possible to have the checkout determine which payment option is being used and then adjust the checkout total based on that. I understand that using PayPal means you do incur a higher fee, the only workaround would be to have this payment method disabled altogether. You could also look into alternative providers that are available in your region then compare the fees. I have linked a comprehensive list of online international payment gateway providers that integrate with Shopify below:
There has been quite a bit of discussion on this topic in previous threads. One of our wonderful Shopify partners has suggested implementing the fee into product prices. You can check out his suggestion below:
Tip: A normal process in owning a business is your partners (including the services you incorporate into your business) managing their risk, however, new entrepreneurs have difficulty navigating their way around these situations. If you find yourself with PayPal holding your funds you havesome steps they recommend to follow here. The better you manage your business, the less likely it is you'll encounter difficult situations with your payment gateways. Don't forget that you can eliminate your transaction fees with us by usingShopify Payments as a gateway.
If you have any questions please feel free to thread those below.
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