I doubt somebody like McSweyn makes 400K a year.
The difference between 80K a year and 400K a year in the West is nothing, compared to the difference between 0K a year and even 10K a year in Kenya. In Kenya 10K is the equivalent of being a millionaire in the West.
Then in the West, your name gets tarnished as a drug cheat for life. Not only is your athletics career over (including coaching etc), but it will likely damage your career prospects for life, as well as even your social life. In places like Kenya, there is virtually no stigma in 'cheating'. It's not even regarded as cheating - it's just life. You win a couple of marathons, you get popped, and you retire in comfort in your Kenyan village with your family for the rest of your life.