Salary is always the best motivation for work 
If you pay your worker well, you show him that you appreciate him, his work and effort.
You're right, if you pay your worker fairly its a motivation to work hard for getting what they deserves not only for them but also for their family. Plus showing that you care as an employer is important too for them to not feel that they are just a worker but a family that you care of.If you pay your worker well, you show him that you appreciate him, his work and effort.
People still settle. If you give them a raise, they settle, and the motivation eventually goes back down. That's not a criticism, just a fact. So then you go back to the point of how to motivate yourself again. This is an issues in sports with players making tens of millions of dollars. That constant search for motivation.