I'd have to move more towards the four $100 knives than a $400 knife.
Don't get me wrong, high end semi-custom knives are a thing of beauty and I do intend to own a CRK Mnandi before I die. But given the choice between four or one, I'd take the four. Because you get more options. You can pick and choose your steel, your edge grinds, your handles, locking mechanism, etc. If you spend your entire knife budget on one knife, it may not be perfect for all situation.
These days there are a lot of very very nice knives to be had in the $50 to $200 range. They may not all be show pieces, but in that range there's some work horses (BM 710, Manix, Paramilitary, etc) and there are some very beautiful, classy, funcional knives at the same time (Queen, Case, Buck, S&M).
I look at knives as tools and my buying decisions come down to what I think I'll need and use. Every now and then I'll treat myself to that one expensive knife that I know I won't use, but damnit I have to have it.
In the end it isn't even a personal preference as much as a case by case examination of the knives available.