The cost to produce a lb of beef is largely dependent on the price of feed, which is the major expense for the cow to get the calf raised from birth to weaning. Then in the feedlot phase, because the diet is mostly corn, the price of corn will impact this cost as well. If the cost from birth to weaning is $400 and the cost from weaning to finish is $390 then the total cost is $790. If the calf weighs 1200 lb at finish, then the cost per lb of gain for a calf that goes through a "calf-fed" system, then the cost is $0.658/lb. In these figures, it assumes that the producer retain ownership and the "in" cost of the calf is what it cost to produce the calf to that point. Cow expenses may be higher because of drought causing the price of forages to go up. If you had to purchase the 500 lb calf at weaning and paid $1.20/lb, then the "in" cost is $600 and total cost is $990 and the cost per lb is $0.79. If you retain ownership of the calves and they are the type of calf that can go through a growing period during the winter and grass pasture in the spring and summer, then to a short feedlot phase and the total cost after weaning to slaughter is about $520, then the total cost is $905 per head (using cow cost to produce the calf to weaning). Usually calves that go through this system will weigh more at finish and let's say 1375 lb so cost per lb would be $0.658/lb. These are just estimates and producers need to put in their costs, because it will vary within states and across states depending on your resources.
You can do a breakeven calculation to estimate costs. This website has is a breakeven calculator http://www.chaps2000.com/calfweb/breakeven.asp