High Paying Keywords are usually saturated already. Lots of people have been into internet marketing and SEO a long way before you and I. They have totally dominated these high paying keywords. So even if you find these high paying keywords, your site might not rank up high in the search engines. If you want to check high paying keywords, google for Spyfu. It is a useful tool.
Agreed. Better start a niche in which you are an authority rather than chasing the high paying keyword which is very difficult to rank in the serp