I didn't read it as "one simply has to earn more". He's saying it's better to work on things that will lead to one earning more money, rather spending time mon

I didn't read it as "one simply has to earn more". He's saying it's better to work on things that will lead to one earning more money, rather spending time monitoring how much one is spending. The first leads to an improved state, the second is just for ensuring one's state does not worsen. With one your increasing your 'cap', with the other you're just maximizing given a 'cap' (cap meaning the amount of money you can work with).