You are right. Must fit in pocket both by reliability and economically.
I am a very aware guy with my things. I don't usually loose keys, lighters, pens or other little things (I do a lot of field research, so this is part of my discipline), so I give myself some quality-based luxury.
Folders are delicate articulated things, and they are just pocket stuff. In my car or at field I keep just the sturdier fixed blades.