For clarity, I address another just if not more important function of a knife.....Self defense. I mainly talking about folding knife that can conceal carry.Not sure what to make of your writings?
You are willing to buy expensive things....Rolex watches, cars.
$700 is nothing to you.....
You practice self-defense, and it's one of your reasons for carrying a knife.
45-90 dollars is what you think is best for you......
You trust your life with a $45 knife???
When money is clearly not a factor?
(Me personally) Idc what time it is?
I'll wear a timex, and carry that 300+ dollar knife! Thank you.
In my opinion, there are a lot of knives that are NOT FIT for self defense or knife fight. To use for knife fight and self defense, one feature is VERY IMPORTANT as shown in picture:

The FLIPPER TAP is very important. In knife fight or SD, you not only do slashing, you do SHANKING(THRUSTING). This TAP shown by RED ARROW is very important to prevent the knife from being shoved back into your hand. You cut yourself really bad if the knife get shoved back into your hands. The TAP is absolutely vital to stop the knife from being shoved back. Look at this knife below, it's is USELESS in my book and dangerous for fighting and SD:

You can see a lot of very expensive knives don't have the TAP, they are not good for SD purpose.
Get a rubber knife with no TAP, do combination of slashing and shanking and you can see. When in the middle of slashing/shanking, you might forget to squeeze the knife before you shank and it will work back into your hand. THAT'S DANGEROUS.