Luxor is served by the port of Safaga, but isn't actually a cruise port. Added up, the cruise port of Safaga is the port of embarkation for just twenty sailings every year from MSC to the Mediterranean.
Overall sailings from Luxor are extremely affordable compared to other ports. Look at the graph below for the monthly average cost per day (Cruises only depart from Luxor between January and December). Prices are approximately the same throughout the year.