Personally, I think skills are the most important thing that one can posess in the wilderness. They weigh nothing, are easy to transpost, and cost little to acquire.
I collect skills and knowledge about outdoor survival. I don't consider myself an expert, and I never will. I'm just a guy who like being outside whether it be hunting, fishing, kayaking, sailing etc... Still it's fun to know 6 different ways from sunday on starting a fire without matches. Or knowing a type of shelter for each finger you have etc....
Everytime I venure away from civilization I have some type of large fixed blade knife with me. In fact I keep a Ranger RD-7 in the trunk of my car at all times.
Here's the way I see it. In a true survival situation everything is going to have a cost. For the most part these cost are going to be either time, or calories. And if having a knife saves me time so I can collect, gather, or hunt for calories then so be it. If having a knive saves me time fashioning a shelter so I can have more time spent on something else detrimental to my survival then so be it as well.
That's just my two pennies worth.
Jerry