[yummyfajitas]

Again, in the first case the man is simply spending the 25k on the maid. In the second case he will spend the 25k in something else.

Again, you are looking at the GDP of the man, not of the pair of people.

Because the man first spends 25k, and then the maid spends 25k again, the 25k is counted twice in GDP statistics. In the second case, it is counted once.

This is why GDP != Income.

[viandante]

Well, let's say that now that he saves 25k for the maid, he hires a gardner. GDP 225 again? So basically the GDP depends on the number of transactions? Is that so?

[maratd]

Yes, that is so. GDP = Gross Domestic Product. It's gross. Not net. There is no saving, no subtraction of any kind. Just addition.