Kerry, my son is NEVER going to race a go-kart, so if I'm spending more money on a limited-use gas powered device, then I'm going to do a golf cart that my family and I can use to get around UA and use it for parties/parades. UA's 100-year anniversary is next year so it would be fun to go to some of the restaurants/parks that will be hosting events.
Families I know rent a 4-passenger golf cart for $300 over 4th of July weekend, every year...I could kill a handful of birds (fun runabout, neighborhood cart for son/daughter, parade-special) by buying something under $1500 and fixing it up.
Every home-built go-kart seems frought with ridiculous compromises (unless you spend $1500+ for a shifter/dedicated-race cart), and a minimum of several hundred dollars to not get much use out of it. A golf cart that hauls 2-4 people would be fun and something I'd get a lot more use out of it.
P.S>>> If any of you younger guys without families or civic connections think this is wierd, I totally get it. Just trust me when I tell you after settling into a community with adult friends involved around town and kids in schools/sports/programs, that something like a family golf cart makes a lot more sense.