I think it is entirely up to what you are buying the knife for. If I am plunking down $400+ on a pocket knife I will be pretty particular of materials used, fit, finish, lock up/action, warranty, company culture (is the manufacturerer run by "good guys"), etc.
If I am buying a beater, then I will be more focused on value and maybe even availability (like if I am buying some off the peg of a sporting good store because I forgot my work knife at my desk the next town over).
My personal buying habits have elevated to the point that most of my edc knives are $400+, but I still find a lot of value in them. Furthermore, I'm way less particular about a fixed blade that is purchased for dirty work.
Case in point:
In the last 2 weeks I have purchased two knives. A TOPS Steel Eagle from a LGS and a Microtech Combat Troodon from a knife boutique shop. The Steel Eagle cost me right at $200. Fit and finish are great. Choice of steel is serviceable given TOPS reputation for how they heat treat. The sheath is well designed, and if I were to base this on a price per pound value, I certainly got my money's worth out of this heavy pig sticker

I purchased it for taking down to the cabin this fall to aid in reclaiming the trail down to the boat dock...and I just kinda wanted it.
The Combat Troodon was purchased for a completely different reason. It cost me $525. The M390 steel is a very good edc steel on a knife that I won't be banging through tree branches. It had a single tanto edge that is fully serrated. I bought this knife mostly because I wanted it. I also have grown to rather like serrations for more of my daily chores and MT does a great job of not only making the serrations functional but easy to field sharpen in a pinch as they bevel the non presentation side and keep the teeth in line with the edge of the plain tanto tip.
However, is the Combat Troodon worth $325 more than the Steel Eagle? Hard to say. The TOPS certainly could take more of a beating than the MT. If I were dropped in the wilds with only one knife I would pick the SE over the CT by a wide margin. If you weight it all out, the SE is probably the better value as a lot of MT knives are priced according due to the small runs they offer them in.
That said, I feel way more fulfilled with my CT purchase even though I already have a model with a double edge. I just like it more. I like the action more. I feel that is oozes more of a high end quality when you get down to the details and materials it is made out of.
So, tl;dr
I personally don't have a set of attributes I need checked off when I buy a knife. It just has to be capable for the job I am purchasing it for and be a good value to ME
