Sound engineer where? Resident engineers in studios (if any still exist) get paid much differently than live sound guys in clubs, which is different than touring guys, which is different than guys who do corporate meetings, which is different than guys who work for TV stations, movie studios, etc...
The question is way too broad. Most people also negotiate their price. The only way you will be paid exactly what the next guy in your position is paid is if you get in the union.