True, but so what? Are you saying that because he is a Congressman, he has to only buy things that we approve of? We set a salary for Congress. If we think its too high, we can pressure them to reduce it. But once we set the salary, the Congressmen can spend it on whatever they see fit, whether its expensive wine, expensive clothes, a gun collection, private schools for their kids or whatever.
I agree with all you said, except we do not set the salary, government sets the salary. But yes once he is paid it is his to use.