Exactly, there's the notary cost, the monthly banking fees, the yearly books closing and accounting related to that, chamber of commerce registration (recurring yearly as well). You also need to have a mailbox somewhere to be able to receive all the paper work. You can use your home address but it's generally not recommended and frowned upon by land lords.

In my case, I burned through about 2500 euro in the first year just on stuff like that for a holding company that holds shares in my actual company. It takes about 4-5 months to get most of that behind you. Yearly running cost are about 1000 euro (accounting, recurring fees, etc.).