this gist documents the costs of campzer0 and naively calculates the current ticket price based on the number of registered participants.

camp0costs.py

#!/usr/bin/env python
import sys

persons = int(sys.argv[1])
EUR = 300.169 # Mid-market rates: 2013-09-09 14:49 UTC
VAT = 1.27

# general costs (everything is in HUF)
power = 20000*VAT       # power transmission to the campsite
shower = 234400*VAT     # shower container rent
bracelets = 12000*VAT   # bracelets for the participants (100pcs)
internet = 65000*VAT    # fatter pipe 20/5
# per person
camp = 4500             # permit to camp on the grounds
tour = 200              # admission fee for a tour in the catacombs and the whole site
# per day
room = 30000*VAT        # one 80m^2 room, with full conference gear.

# we need to pay this by next week, supporters welcome.
upfront = shower + bracelets
# we have to pay this after the event to the Fortress
fix = power + (room*3) + internet
extra = camp + tour

# this is the total cost of infrastructure / person
perperson = (upfront + fix) / persons

# each person has an additional cost for the campsite
ticketprice = perperson + extra
print 'ticket price', ticketprice, 'HUF', ticketprice / EUR, 'EUR'

# if all goes well, after the event, we have exactly
totalcosts = upfront + fix + (extra * persons)

# from which we substract upfront costs which we give to the kind
# supporters who pooled their resources for paying this upfront.
# and the rest

totalcosts - upfront

# will be paid to the Fortress for their services.