The whole might be more than the sum of the parts, but the whole is cheaper. At least when it comes to dishwasher and such. Mine broke down. It needed a new clock, the part that tells the machine to play the next part of the program. The dishwasher was something like 250 Euro. A new clock is 165 Euro. Having somebody put it in the machine will about the difference.
I wonder, if all parts of a dishwasher broke, how much would it cost to replace them? i.e. how much do the parts cost more than the whole? It gives an idea how high a percentage shipping, handling, etc of the end product has become. Since the guy also charged 45 Euro just to look at my machine, we're rapidly reaching the point where if something breaks down, you better throw it away directly.
Is this bad? Economically it makes sense, otherwise it would be different. But in terms of the environment it is not so good of course. There was this story about an old guy who had just escaped Eastern Germany, before the wall came down. He had some family and he moved in there. Back home he was a miracle worker, because he could repair all kinds of small broken things. In West-Germany he wasn't. They just threw stuff away.