You need to factor in not just the cost of raw materials, but also include labor and consumeables. As you choose tougher steels, they require more time to grind, and you wear out your grinding belts faster. And wearing out your grinding belt faster isn't just the cost of additional belts, it's the time it takes to change out the belt and the time that machine isn't being used to grind blades.
Most people who purchase knives have no clue as to the difference in alloys. Most people don't know what a sharp knife is, are abusive to knives, will cut with a fairly dull knife, and don't know how to properly sharpen a knife. Small differences in edge holding between blades means little to them.
For the custom knife maker, his reputation is on the line, so he's going to generally use a higher grade steel to produce a superior product to a factory blade. Honestly most consumers aren't going to pay $250 for a custom knife that uses the same blade material as a $100 factory knife, but they will pay $300 for the custom blade that holds an edge longer than a factory blade.
