Thank you S.Moss!
This advice is very helpful. So far I've seen a Rotax Max go for €1,900 with 5 sets of tyres and lots of spares. I'm not getting the Kart right as of now but these tips are very helpful. I live about 15 minutes from a local karting track which is on the M.S.I calender and the rest are only 1-2 hours away. The Junior Rallycross seems cheap too but I'm sure tyres and other stuff would be more expensive than Kart essentials. As for Kart class, the Rotax Max seem good and fairly easy to maintain. I know another guy who did Karting from 10 years old and spent near €80,000 in 5 years from Karting although he probably did it at an extremely competitive level. I'll take this on board and start looking for karts at a good budget.