it's very fun... what would you be looking at? a 125 or something with more umph?
racing is fun, most tracks still charge around the £50 mark though, and thqats if they let you take your kart on the track.
that said, tyres are also £150 a set for slicks soo it's not cheap at all, the best way to cheap go karting is to get a job at a karting centre!!