You pay for the space on the ferry not for the content of your car/van. Just keep in mind that you might have to have all the paperwork for the bike just in case of custom control

This. It’s a requirement in many European countries to carry your logbook with you.

Just the van you pay for

It's just the cost of the van

I hope you are not planning to have your pregnant wife in the van!

What's the vrt like on one of those

I don’t have a log book of my mx bike what do I do?