When I bought my sons kart I did it rather quickly, not a lot of looking. I will say that I got a great kart and my son has drove it his entire time in kid karts. I didn’t pay a ton for it either, but it did not have any of the light weight go fast stuff on it. I paid $1800 for the kart with an engine and gave an additional $300 for the Mychron. Since then I have put every light weight thing on that kart you could imagine. That ended up costing me about $1000 just for the light weight stuff. You will learn that soon enough unless you buy one that already has the light weight goodies on it. If you do, try to get a spare axle or reinstall the factory one while he is learning to drive. Kids bend axles. Also get a sprocket guard, Franklin Motorsports sells them. We got knocked out of Kid Kart Nationals this year because another karter ran into my son in the rear tire and it popped the chain. That broke his heart. Karts hold their value pretty good and there are a few karts that seem to have an edge on the market in winning if you are planning on going Regional / National. My favorite has been Birel, but there are other karts out there are just as good in the kid kart area. Merlin and Emmick are really good karts. If you can find a kart with an engine for under $2000 you are doing good.