Back in the late 1990s, the Space Frontier Foundation operated a prize for amateur rockets, the CATS Prize. I had the great pleasure/pain of running the prize, which included writing the rules. We tried to make the goal of flying our 2 kg payload to a height of 200 km as doable as possible, without making it too easy.
The CATS Prize was announced during the 1997 Space Frontier Conference, the same time that the Keep Mir Alive project was first mooted, so the joke of the conference was that the Foundation was going to put a target on Mir for the amateur rocket guys to aim at.
One of the rules stated that we had to be notified 30 days before launch (so we could arrange for an observer). There was great moaning among the rocket groups about this rule, as they claimed that they could be ready within 2 weeks from the official start date of the prize, so the extra 2 weeks was a big burden. Needless to say, none of the moaners ever actually launched anything. Another rule was that the rocket could not be based on a government system, which prevented Boeing from picking up the prize during their next satellite launch, but also stopped groups from using existing assets for the competition. We also specified the payload, a 2 kg cylinder, selected partially to obviate anyone from flying a dart. The altitude determination system was to be provided by the contestant, and several schemes were devised for this. My opinion was that time of flight, all other things being equal, was a pretty good measure.
Literally dozens of contestants came and went. I was besieged by people claiming that they were ready to launch Real Soon Now, but specifics were often hard to come by.
Another issue about the prize was that it had a deadline of 3 years. In 1997 that didn't seem to matter, but in 2000, a bunch of groups claimed that they could launch to 200 km Real Soon Now if there were an extension. In retrospect, rather than have a hard deadline, we should have dialed back the prize money some fraction every year. The rocket groups didn't believe the hard cutoff, they were sure we would extend, but if we had built in a soft cutoff, where after 2000, the prize were to be reduced to $150,000, they would have believed that.
JP Aerospace was one of the leading contenders, but they never actually launched. However, in the waning months of the competition, they received a grant from John Carmack, who heard about the CATS prize. After watching JP Aerospace in action, he decided that he could do that, too, and started up his own rocket group. I really don't know how that turned out, perhaps someone can find out and write it up here in another thread.