According to this (http://www.altgate.com/blog/2008/10/2008-startup-compensatio...) 10-year old survey executive compensation of 600+ venture-backed startups, a founding CEO of a software company with <$5MM in revenue is in the $160-230K range (25th %ile and 75th %ile respectively). As an aside, equity is in the 8-30% range (same percentiles).

This isn't terribly helpful to you question since it's for venture-backed companies, but it's at least an upper threshold.