I have been in search of MY ideal survival knife. ...is a Busse, used as a surival knife, worth it? 'm a big fan of the RC-5 and RC-3, and would like to own a Fallkniven someday.
Being there done that
I have a couple of Falkniven's and Busse's.
I think you should answer two questions before making a buying decision.
First, do you need small 4-5 inch knife? If this is the case, my advise is that you go for Fallkniven(S1). S1 is very efficient cutter, tough and light. The main advantage of Busse is toughness, something that you do not need in that size as usually you already have hatchet, larger knife or folding saw to handle larger tasks.
Second, if you need bigger knife (7-8 inches) Busse may make more sense price wise as this type of a knife faces tasks like chopping or selfed defense where the extra thickness and not being stainless are not as big an issue as they are for the small 4 inch blades.
My personal take is that realistically, not in the fantasy land, you will never need supper thick 4 inch knife. Thus, you do not the $400 Sar4. On the other hand if you decide that for collection purposes, do not lie to yourself with this "survival" BS ! , you need Busse you would be better of with something with 7+ inches as this is the type of knife where Busse shines.
I never used or carried my Busse's in the woods as they are too heavy to carry but at least one Falkniven is always in my backpack (A2 is my favorite)
Finally, remember that there are many collectors and backyard choppers here, thus for more realistic advise you should go to some backpacking forum, where people really go outdoors and use knives in more realistic way.