Wouldn't some of this depend on the type of feed the birds consume? Typically, a meat bird like a Cornish X is going to receive the high protein diet of a meat bird food, which costs more. Most people growing DP birds as meat birds seem to have them in with their layers, so they eat more of a layer type diet after the first few weeks. This will have less protein and cost less. I would like to experiment next year by feeding a broiler regiment to DP roosters destined to be dinner while at the same time, feeding a regular DP diet to a portion of those birds to have some comparison weights at certain ages.