This Delaware Online article tells of two brothers, who whilst on a vacation flight had the idea to set up an indoor go kart track and ultimately give up their day jobs.
They are not quite there yet, but after three years and $600,000 their track is now open for business and for $20 you can […]

Northern Tool sell a (nearly) complete Go Kart Kit for $649.99, currently discounted to $599.99.
You get everything except an engine and a clutch, including a bucket seat and full instructions!
They also sell engines and cluthes seperately and are a great resource for the hobby Go Karter.