Just a guesstimate (and probably low), but Basecamp likely has the highest $$ / employee in SaaS:

#gid=0" rel="noopener noreferrer">https://docs.google.com/spreadsheets/d/1RwrDxt1KwAB_MSoHN79adVhVXanHeMXZ2UvWIos_-oM/edit#gid=0