As Paul said, it's region-dependent. It also
depends on what you're promising, and how long you've
been around.
Example: BHSAT4 (Yale 1995)
charged $40 or $45 for a double-elimination tournament,
and got 29 teams. The next year, I converted it to a
round-robin format (guaranteeing just *four* games). The base
fee went up to $60--and we got 44 teams.
--STI