Sorry, but this is not "Regular Maintenance"... I can't remember the last time I've ever had to have a water pump replaced on a vehicle and have had many over 100K miles, If you are losing coolant, you have issues that need to be searched down with dye and blacklight...I would not consider it bad luck . . . it is just a case of regular maintenance for a vehicle your age and mileage. Get a new water pump and keep on driving !!!!