The others are correct. I build rods and sometimes what i'll charge is more than what you can purchase from the rod manufacturer. Sometimes the cost is less. It really depends on what you want in a rod. I know that isn't much help.
Sometimes people want a really nice blank but will cut costs with a different grade of cork or seat. Rubber o-rings (personally, I don't care for them) will lower the cost over a nice nickel-silver check. Alot of times a manufacturer makes a rod that just doesn't appeal to a person due to the color of the windings, stlyle of cork, or wood in the reel seat. This is where you could build the rod you want for about the same cost as one built by the manufacturer.
I hope that helps clear things up some.