@sam3110 You don’t necessarily need your own kart to go racing. The UK has some pretty good ‘rental kart’ championships, in which you use the circuit’s own arrive and drive karts. There’s Covkartsport Which is one of the longest running series of it’s kind, and (speaking from experience) has some very quick and competitive drivers, and The British rental kart championship, which is only in it’s 2nd season but is also very competitive.
To do a season of either of these would be somewhere around £300-£400, which isn’t actually that expensive for a full season compared to owner driver karting.
EDIT: I just read that back and it makes me sound like some kind of salesman! Lol