yes you do, it's almost as complex a subject as computers, infact we had a washing machine thread in general chat section
Actually I'd say the cloest to buying a new washing machine is buying a new psu, don't rely on big numbers, it's the brand + model + who actually made it that are the important things and a bad choise can cost you more that just the washingmachine.
But I'll stop there as that really is a different topic.