A lot of TD'd do charge retail for the cost of the player's packs and have little to no payout - like GBO. At the Challenge, I cost it out so we're not making money on the player packs.
Basically, for that event, we have the cost of the discs and the shirts - everything else is donated. So, let's say the disc order is $2,000, and the shirts are $1,500. We have $3,500 in total cost. If we have 150 ams, each one pays about $24 ($3,500/150) for their player pack - out of their entry. So, if you're playing advanced, the entry fee is $65, take out $4 for PDGA, about $5/person for cost of player guides and trophies, you're looking at about a $32 net entry going towards payout. ($65 - 24 - 4 - 5 = $32)
Now, if there's am added cash, you have to allocate that among the divisions. Let's say there's $1500 added, and there's 80 adv, and 70 int to make it easy. That would be $800 to the adv, and $700 to int. Divide $800 by the 80 adv. players, you get $10/player, so you total net entry would be $42. ($32+10).
Clear as mud?