I'm referring to wages, not rewards of being a founder. As for glassdoor.com, I don't think it's very accurate. I'm guessing "database engineer" == DBA.
$125k/year is what you would give to a decent coder with 3 years of experience. At Rethink, it looks like they want to pay him $80k/year. Some people will take the job just because the company and problem domain looks fun, but not everyone will.