Why would you have to replace the whole display? If the screen is perfectly readable, but is less bright than before, it appears that the problem most likely is a dimming CCFL lamp. Those cost $10. A new LCD is $300. This of course only applies if the screen is behaving properly-- no missing regions, no streaky lines or obvious damage. The real question is are you prepared to disassemble a $2500 computer, including opening a dust-free sealed LCD assembly to get at a $10 flourescent tube and do you have the soldering sklls to properly do the job?