Neither Instructors nor Pilots appear to be financially rewarded for experience.
The only thing I have been able to see is that with experience most can go from job to job with less problem.
Some who have used this experience to move into either twins or larger and have reached the top as ATPs do obviously garner a bit more. Just compare Apples and Oranges with other jobs and their requirements and you will find at the back end that although it may be fun and sometimes personally rewarding, your not going to retire rich, if you are able to retire at all.