If you already own every single piece of camera gear that you desire, and if you have spare cash that you don't need for anything else, then yes, by all means spend it on a w-g monitor.
But if there's a new lens you're lusting after, or a piece of lighting equipment, or something, do the wise thing and save your extra money towards that. A normal-gamut monitor is fine.
http://www.damiensymonds.net/art_monitor.html