I went through 750 lbs of feed for 35 birds in 8 weeks.
Ok, maybe it's just me, but that sounds like an extremely unusually high amount of food for that amount of birds. For my flock of 15 chickens and 3 turkeys, I go through a 50 pound bag every 6 weeks or so. Are you free ranging yours or are they strictly caged and fed commercial feed? Granted, I understand the broilers eat more than the layers, but over 5 1/2 times more food seems excessive.
50 Pounds / 6 Weeks = 8.4 Pounds per Week
8.4 Pounds per Week * 8 Weeks = 67.2 Pounds Total for Current Flock
67.2 Pounds Total for Current Flock / 18 Birds = 3.73 Pounds per Bird
3.73 Pounds per Bird * 35 Birds = 131 Pounds Total for Your Flock
131 Pounds Total for Your Flock / 50 Pounds per Bag = 3 Bags
3 Bags Feed * $25 per Bag = $75 Feed Costs
From my understanding you lose about 25% of the weight once dressed. I'm guessing the 8 pounds is the live weight.
35 Birds * 6 Pounds per Bird = 210 Pounds Meat
$75 Feed / 210 Pounds Meat = $0.36 per Pound
Anyway, that's based off my flock. I'm extremely curious to hear more details because I was planning on doing about two-dozen broilers this fall and am hoping to get as much information as possible. Please update us on your dressed weights. If your feed rates are more accurate, I may need to seriously rethink this. I don't have the $250 for feed that your rates would cost!