How much money is karate?

Too many variables to consider:

Who's teaching? A qualified instructor of high rank from a recognized organization is worth more than a Shodan opening his first school and teaching his 'own style.'

Location - Cost of living and the economic situation of the community can vary widely.

What overhead has to be covered? - Insurance, rent, utilities, advertising and other items have to accounted for. If those don't exist, there is a lot less to worry about.

Employees?

Facilities? Providing showers, locker rooms, weight rooms, saunas and other items with the membership is worth a lot more.