Well, it's not really fair to compare the cost like that. I don't have a laundry line-item in my budget that I have to justify to a comittee- but I do have hundreds of dollars to spend on dumb ideas every week. Spending some of my disposable income on getting my laundry nicely cleaned and folded might be enjoyable enough to justify.
In the same way that I know I can cook dinner at home for just a few dollars, I still go out to restaurants several times a week and spend $20 or more on a meal. Sometimes I'd juat rather not cook, and I won't really notice the difference in the price, at least not in any long-term sense.
