Promoters do this all the time –
Concerts do this all the time. Use outlets to sell advance tickets only. Make sure you count the number of tickets you give them, and when its time to cut off sales (or once a week depending on how long they are going to be selling tickets) you go back, collect the leftover tickets, and whats missing they pay you for. My wife collects money every week from various restaurants, etc this way for shows she runs. Works great, its easy to audit (they sign for the tickets you give them and they pay for the tickets they don't give back).
We sell our own simply because we dont have anyone in the near vicinity to sell tickets for us. We do sell online through TicketLeap which works out great as well!
Travis "Big T" Russell
Big T Productions Inc
Owner and Operator of "The Plague" and "Camp Nightmare"
Customer Quote of the year: "Damn, I pissed myself"