Formosa kid, I sent you a PM.
But a very rough idea of new Tag setup values.
DR or Praga, single rear brake, 30mm chassis, 50mm axles=$3200; X30/Leopard engine package including the radiator= $3200; Mychron gauge= $550; Bridgestone/MG/Vega tires=$225 misc stuff, chain, sprocket carrier, rear gear, linkage,etc= 250. So, give or take for all new stuff you're looking at about $7-8000. Very good used, maybe one or two years old, good engine builder, good chassis for parts availability, etc, $4-5000, OK used, $3000, get what you pay for, less then $2000.
Other thing to think about. Do the tracks where you intend to run have a Tag (Rotax, Leopard, X30, etc) class? It's VERY unlikely a kart which is right for you will work for a junior driver (wrong size and not legal). Where do you live? What classes does your local track(s) support? How old are the junior drivers? GO TO YOU LOCAL TRACK BEFORE YOU BUY ANYTHING!!!!!
I PMed my phone number, so call if you wish.
Have fun and good luck.
Clark Gaynor Sr.