I think he was asking more about the financial aspect of throwing a comp. It depends on your scale and our location.
Most money invested will be involved with the venue, then PR, then money spent on teams. Revenue comes from donations/sponsorships, ticket sales, and team registration.
At say 200 per team and 8 teams that gives you 1600 from teams (but part of that must go towards things like food for the weekend, tshirts, afterparty tickets etc etc). So there's not a lot realistically coming from there.
1000 seats at 10 dollars is 10k which will barely cover costs of venue and PR (and would require sold out audience). Sponsorship can bring in a lot depending on your sponors and packages. I can't divulge the details from BIB but I can say we ended up raising 10k, 13k, and 15k in consecutive years for our charity and that was because we had a lot of sponsors excited to contribute knowing the money was going to charity. Given the recession, comps have found this more difficult. This is why a lot of comps tied to schools tend to prosper as the university can provide either: a venue, money to secure a venue, or help with PR and sponsorship.
This is all very general but should give you a good idea. First step is to determine suitable venue and find out the renting price. That will be the benchmark for the rest of your research
hope that helps!