How much cheaper is it to buy nuts and bolts by the pound?
You do not really need to buy a pound of the item to determine the cost per pound. From the weight of a single item, you can figure out home many there are to a pound. Then from the price per item and the price per weight, you can figure out which is a better buy. The nice thing is people have already weighed a lot of items. Here is a chart of bolt weights and another with nails and screw weights.