You will never be out of pocket or have to pay My Event Guru for tickets that you don't sell. Free tickets, tickets purchased offline, and tickets purchased at-the-door are FREE and do not incur any charges.
The only time fees are incurred is when they are purchased using a credit card on My Event Guru or via Paypal, and in this case you are still not out of pocket. We simply deduct credit card and service fees from your final payout after the event closes. When you set up your event you also have the option to pass these fees on to event registrants if you prefer - it's up to you!