You've got $500. Imagine a world in which you are not limited to the question of, "what are my available options?" GO CUSTOM!!!!!
You can contact a custom knife maker (we have great ones here on the forum) and have one made to your specs.
Let's say you want a 6" fixed blade, with a high saber grind, in AEB-L, a finger choil, thumb-ramp with jimping, Red C-tek scales with black G10 liners and hollow tube bolts. Guess what? Someone can make that for you.
I mean, $500 is not limitless money so you may need to make certain compromises on materials, but that would be the case with production too. $500 will go far with customs though. My point is that if you buy production knives, you're limited to the options others have picked and built for you. If you buy custom, doors open up in terms of you getting exactly the thing you want. YOUR knife made the way YOU want it.
Knifemaker's market for fixed blades
Knifemaker's market for folders