Sure, I spent that much for a US Army Edition billet lower. For the same reasons Jon mentioned I don't mind paying a little more for lowers I really want. After all it's the firearm so why not have the roll mark you like. What's $50 when you consider the overall cost of the rifle.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together. You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek