Paypal as merchant

You should probably google something like "Paypal horror stories". Actually, I think their is a site dedicated to paypal horror stories. Paypalsucks or some such. I had an account blocked for life simply by taking some money from the USA. If I remember rightly, it was some waffle about me targeting US citizens. That was a decade ago.

If you are running a startup and want to quickly get set up, then paypal is probably the way to go. However, the costs per transaction are pretty high. As a more established business, with a steady revenue, you'd probably want to switch to different payment processor such as Ingenico where there is a monthly charge, but the cost per transaction is significantly lower. Also, unless you have your own web team, setting up Ingenico is significantly more work than setting up Paypal.

"3,4% + €0,35 EUR per transaction (the sender decides who pays this fee).
Small cross border fee of between 0,4% to 1,8% (depending on where you’re sending the money). A transaction fee of 5.2% + 0,35€ will also apply if you use a debit or credit card to send the money."

Standard transaction fee within Belgium:
3,4% + €0,35 EUR per transaction.
Discounted fee for eligible merchants and not-for-profit organisations (upon application and approval):
As low as 1,7% + €0,35 EUR per transaction based on volume.
Micropayments within Belgium (upon application and approval):
5% + €0,05 EUR per transaction.

Surely in Belgium, bank transfers are the way to go as the system is well-developed, well used and almost cost free. Quite a number of organisations that I have had dealings with, both small and large, actually use the bank transfer system to take their orders (as well as the payment therefor) and it seems to work perfectly.