I use to think that spending more than $10 or $20 on any knife was a waste of money too. Same as well with other things, I was always trying to get by with guns or parts that cost less to try to save money.
In more recent years I have seen that quality that will last costs more, and it is better to pay a bit more in the beginning and it last, than buy another to replace it again in the future. I especially learned this with car parts, lol.
But with the knives, I use to carry cheapos, my dad still does sadly. But after seeing how much better quality knives with quality steel holds their edge, and how much stronger they are. I've changed my mind, and switched from the $10 cheapos up to quality Benchmades with better steel for folders, and so far ESEE for fixed blades. After seeing some even nicer stuff in action, I will be upgrading further, but gotta take things one step at a time. As said by others, I use a knife multiple times a day, I live on a farm, work in a warehouse, and work on cars. So I'm never without at least 2 knives on me at all times. I'm the one that my family and friends always ask for a knife when they need it, cause they know I've got one with me.
Test a quality blade out sometime against some cheaper ones and you will see what we are all talking about.