Hello Hessel,
The way people most people do it by setting up different membership levels - you can create as many as you want and make them only appear on events registrations - and setup different prices per level. This assumes that people would have to login to get the appropriate pricing level applied.
Alternatvely, on each event (go to event details, registration form link) you can go can add a field e.g. "Registration type" with options like:
Regular registration: $0
Front row seats: $10
etc.
Let us know if either of this sounds appropriate, tell us more about your situation - what specific types of registration you need to handle and we will help to figure it out.
Dmitry Buterin, Chief Apricot