Well each Cleft is effectively just a metre of Timber. Imagine if you went to your local B & Q and saw a metre of timber for even say £40, you'd have a heart attack!
Even timber like Brazillian Mahogany isn't more than £20 a metre, and that is a damn sight more difficult to get hold of than some Willow from Essex, especially once you factor in transport as well....
like most woods, you pay for not just the willow but the upkeep of the trees, the cutting, sawing, drying, storing etc.
as a bat you are also then paying for all that plus- machining time, pressing, glue, handles, twine etc etc. you are also paying for the time and skill of the maker and any other overheads they have. with the bigger companies you are also paying for sponsoring the top players. its suprising how quickly some of these costs can add up, I think you may also be surprised on the cost of a cleft ( grade dependant)
for me, I would recommend going to a small independent bat maker. you can get a very similar product for a lot less than the big boys charge. you also can get a much better service and its easier to customise and get the bat you want