I've only paid for 2 folders, that I can think of. I own way more fixed blades than I need. Fixed blades are less expensive, in that you are not paying for the mechanism, locks, clips, etc.. Just the knife and a sheath.
When I see expensive folders, I think, why pay so much for a weaker knife, when I can get an awesome fixed blade, often for less? It helps that I live in a knife friendly state. Plus, I only carry 4" or less "hunting" knives.