Many chemicals both in the detergents and possibly in water can cause damages to the machine. There are some other problems like hosepipes or other fittings getting loosened in the course of time. Improper electrical connections can also cause damages to the machine. No one can predict the problems that may occur due to moisture, heat, chemicals and electricity. Overloading of clothes also can cause damage to the machine.
To make it easier for you, best to know the specific make and model of your machine. The model number and the serial number help locate a compatible item for your property. Prices vary according to product quality. Do not be fooled by brand names though. Being expensive does not necessarily denote quality. Choose what is tried and tested by other consumers.