I have 6 RIR hens and they go through about 10 pounds of pellets per week. I prefer the pellets because I find they waste less. When I tried the crumbles or mash they just spread it around everywhere.
When I did the math it seems to me that your 150 pounds per week is not unreasonable comared to my feed requirements. I have the food in a hanging feeder that is available to the girls 24/7.
Also with regards to those telling you that you feed way too much...I have the same thing around here with the ranchers..."Just turn 'um out in the yard and throw some table scraps at them once in a while, they'll be fine! I never buy anything other than a rare bac of scratch grains!" Yea, and I guess that's why they're buying 25 chicks every spring to produce enough eggs for a family of four... In the long run, I think feeding the hens a quality diet is cheaper than feeding freeloading chicks every year for 4 months before ever seeing an egg.
To each his own...but my girls get their pellets, oyster shell (the feed stores here, ranch stores, sell it for 20 cents per pound...no idea what it would cost in bulk), greens from the new organic food store in town (they save the trimmings in the produce dept for me), and a bit of grain if the night temps are going to be in the teens or lower.