i didn't want to post in this thread but you asked a legit question so i'll respond.
first of all, i didn't know they even had comps out in ontario-way. second, tires aren't cheap, and they're costing somebody money, therefore you're earning something. i live in calgary, and i've never traveled east of here for a comp, only west. here in calgary, at C.O.P., they have weekly dirt jams and dh races, and i think you can win over $20 for a third-place finish, more for the other two podium spots of course (i didn't compete at C.O.P. this season so i don't know exactly what it was, but i know that the last time i competed at C.O.P. i won $50). i've won a lot more in other comps at bigger hills, but i've never heard of any comp not handing out a prize, whether it's money or bike parts.