Depends upon the state you are in. When Bush passed NCLB (No Child Left Behind), one of the criteria was that teachers had to be certified and endorsed in their teaching area. This meant that they had to have at minimun a Bachelors degree and a teaching certificate from a certified and recognized university program.

On top of this, once hired, teachers have to continue to work for a advanced degree by taking classes in their area of endorsement. This is continual, not one time. In NM there are three levels of Mastery and they take multiple years to accomplish.

Schools are rated on their staff, the number of endorsed professionals, and the number that are progressing towards advancement. Their yearly funding is tied to these criteria and normed testing numbers.

The downside of NCLB was the emphasis upon testing results. It was an artificial way for politicians to understand achievement and progress. Politicians understand numbers, not the nuances involved in education.

So when you ask are teachers worth it. Damn straight they are. They spend more time with the children than many of their parents do. They provide structure and guidance for children which have none. They deal with unruly adolescents and pre-teens because their parents are too busy too teach their children etiquette and manners.

They work tirelessly planning, designing curriculum and content. They spend evenings and at least one day on the weekend planning, grading and designing. The average teacher work week is around 50 hours. So yeah, teachers are easily worth $90,000 / year +. Doing their jobs and parents as well.