if your looking for somebody to give you an answer based on science, go ask a phd in protein metabolism... they can cite you exacly "how much protein you need"...science has already came to some pretty solid figures for this... but what they will fail to mentio is that Yes, science has got an answer for what a person "needs"... but by that all that i meant is= what is the minimum intake necessary to avoid a negative nitrogen balance(losss of protein - malnutrition)... they have not yet came ot any conclusion on what is OPTIMAL for gainign muscle.... all that someone NEEDS to stay out of a state of MALNUTRITION..is quite low.. about.75grams per kilo for a sedentary and about .5grams per kilo for a weightlifter...
however studies evaluating "results" based evidence...(giving diff groups diff amounts of rptoein intake and seeing where the ceiling is)...seem to think its around 1-2grams per pound body weight.