False. Think about why humans felt the need to ascribe a term to a concept. Think about it.
True. But the subject begs for qualification.
your logic, to me, in one respect, is correct, but in another, it reflects flawed libertarian thinking.
If a poor man with his last 1000 dollars pays a prostitute, it's not exploitation, per se, but the dude is a fool.
See, exploitation occurs when workers are paid so little they cannot live, and have few alternate choices for employment given their circumstance. It doesn't really apply to the prostitute model you present. Surely he can easily find a better deal on another block, which is usually the case.
For someone with $10,000, $100K now that person is no longer a poor man, is he?
Exploitation only has moral significance when applied to the disadvantaged, in employer/worker models in an extended fashion, not the privileged. And NOT in the single transaction mercantile model.
Where exploitation in markets does occur is with monopolies, which is why they are ( supposed to be ) illegal ( though antitrust laws these days are quite lax ).
THere might be other circumstances, as I have only given this a cursory examination.