While not a cycling event, I help put on southern AZ’s largest festival, the Winterhaven Festival of Lights, which is a Christmas festival, solely contained within our neighborhood. Our costs this past Christmas to put on the walking only through the neighborhood from 6-10pm was ~ $120k USD for the 14 days we run it with over 200k visitors to the event.
In the past I’ve been an RD & worked for a RD & timing company on triathlons, running races, open water swims and a few mtn bike races.
I skimmed the comments yet I didn’t see mention of the costs of:
barricades
portable toilets
security
fencing
signage
trash bins
getting the trash from the bins into the dump
permits for not only the roads but the parks/common areas that events may use -not to mention the park often has a separate fee(s) depending upon what amenities and how much of an area you take up with your race
fuel for the generators
the truck & trailer & fuel to get equipment to set up the race to the race site (granted the truck & trailer costs are spread out over many races and many years. Those two right there can be a $100k investment)
often you’re paying some costs to the set up/tear down crew
making a donation to the organization that got a lot of volunteers out to the race
the amount of time behind the scenes where you’re negotiating with the permit agency/agencies about your security plan, your emergency response plan, this plan and that plan.
There is usually a flat cost for the timers to show up and then a per rider cost for the actual timing.
If the race crew is showing up the day before to set up the race now you’ve got hotel & food costs to add to the total costs.
When the race production company shows up to set up the race you’re often 20-50 paid hours into that race and no one has gotten out of the truck or even set up the start line.
People think entry fees = road closures, LEO cooperation, t-shirts & awards. That’s just the tip of the iceberg.
Hope that helps shed some light