SELECT t.Id AS TripId,act.Luggage, CASE
WHEN act.Luggage < 6 THEN CONCAT('$', 0)
ELSE CONCAT('$', (act.Luggage * 5))
END
AS Fee
FROM Trips AS t
JOIN AccountsTrips AS act
ON act.TripId = t.Id
WHERE act.Luggage > 0
ORDER BY act.Luggage DESC