The wealthiest city in the state of Kansas would be the city of Overland Park Kansas which is in Johnson County Kansas.
Overland Park Kansas and Johnson County Kansas has a median household annual income of $73,000.00 which is the highest annual income in the State of Kansas.
The other parts of the state are more poorer than Johnson County Kansas and Overland Park KS.
If you want a good income in Kansas you should live in Johnson County Kansas and preferably in Overland Park Kansas.
Other places in Kansas can be a good place to live however you won't make as much income although taxes and other things could cost more which would cause you to spend more even though you're earning more money.