First, the market for skilled labor, especially technical professions, is perhaps the best example of what is called by economists an "in-efficient market". It's the exact opposite of the stock market or retail stores setting prices for the same brand X widget. 
http://www.businessdictionary.com/definition/efficient-market.html

Even if you are an exceptional DBA, you may find it impossible to sell yourself as such to many prospective (or current) employers because they're simply not interested in an exceptional DBA. What they really need (or think they need) is someone to maintain the status quo or at least improve things to the point where users (at least the users they care about) are not complaining. It's like a restaurant trying to sell upscale $10 burgers to a customer base where the median household income is $32,000, and you're struggling to compete with the local McDonald's dollar menu. It's not that your burger isn't worth $10, it's just that you're in the wrong market.