It's an eye-of-the-beholder thing, isn't it. Value is very much a perceived quality. If someone thinks an item is worth the asking price TO THEM, then they will pay it regardless. EBay is a good example, as you wonder why people would pay such a price for any given article that you or I may consider to be a piece of junk.
This rationale goes for all things, not just keyboards. Of course, all companies are aware of this and market their goods accordingly. Simple, really.