Calculate the total net profit of the store located in highest median income city.
net profit can be computed as SUBTRACT(Unit Price, Unit Cost); highest median income city refers to City Name where MAX(Median Income);
SELECT SUM(REPLACE(T1.`Unit Price`, ',', '') - REPLACE(T1.`Unit Cost`, ',', '')) FROM `Sales Orders` AS T1 INNER JOIN `Store Locations` AS T2 ON T2.StoreID = T1._StoreID ORDER BY T2.`Median Income` DESC LIMIT 1