It's largely dependent on the price of the venue.
Heres the cost of Bayou Big Cubes 2024, It had 45 competitiors with a registration of $20 resulting in $840 of revenue (me and the 2 delegates got in for free.)
$766.08 Total
$500.00 Venue
$36.96 Stripe Fees
$33.86 Printing
$35.00 Staff lunch
$39.72 Batteries
$120.54 WCA Dues