If you're overpaid, you want to know why. It won't last anyway, so the proper thing to do is accept it, then explore the rationale for the compensation to make sure it's not a mistake. Otherwise, you could be screened out as too high or too low. Don't interview just for practice, but do interview. Explore where or how the job could be expanded to meet your level of competence and compensation.
Straight commission is the safest kind of compensation.
It's acceptable in many situations, regardless of experience. Ten percent more earnings over a career lifetime adds up to more than a million dollars. Most of the time, it will give you points for being straightforward. There is some caution about letting your past earnings box you in, though. Inflating your earnings is a bad idea.