The higher price is paying for high engineering tolerances, the axis locking mechanism and the best blade metal I've yet to see.

Here are my under $50 choices, but there are many:

(prices from knifecenter.com)
Opinel - $14
Gerber E-Z-Out - $27
Kershaw Ken Onion Vapor 2 - $30
Buck 110 - $40

Bettery yet, for $48 you can get a Becker Knife & Tool Crewman fixed blade - one heck of a survival knife. I wonder what a BK&T folder would look like??