Otherwise you expose your company (make sure you are incorporated!) to significant financial risk. See the discussion here, which relates to why Paypal hates conference organizers:
Unfortunately I don't think I can hold off on payment collection until after the race because organizers need the registration money to actually pay for the race facilities. Any suggestions there?
my 2 cents: I suggest you contact your local running clubs/athlete associations, and race organisers to help them out with this + remove the need to signup (give the user the option to do so during registration, but not before). This sector needs an Eventbrite for sport events. Best of luck.
Any commentary on making your SAAS with Haskell, where you thought it helped, where you thought it hurt?
Thanks!