I took these shots at JAE last month, competition spec fully welded in cage,comp seats,carbon door cards & floorguards,suspension,brakes etc etc.Your 23k isn't long in adding up,think of the man hours alone just to weld in a cage & then paint it.
It's the labour that hikes the price of these cars, not the parts.If anyone was building one for theirself then obviously if they had the skills then it would be cheaper.Try to remember that this is a business & that they need to make a profit to survive.
Just my 2 pennethworth[][]