The big problem is that conflict of interest situations are inherently bad and should always be avoided, wherever possible, out of principle.
Therefore Congress has no business deciding its own rate of pay for its members.
That matter should be decided by another body, perhaps the General Accounting Office, same as other Federal employees.
And of course with any action by any Congressmen that ever remotely appeared linked to retribution or reward for GAO decisions regarding Congressional pay to be a criminal matter.
Actually, if not for the unethical conflict of interest situation, Congressional pay is at a lower level than best serves American citizens.
Pay for Congress represents an absolutely trivial percentage of tax collection.
Better to pay more and get better people as a result.
For example a doctor friend who has been getting more and more active in trying to change government was actually starting to think about running for the seat in his district. I pointed out to him that he needs to forget it: he flat can't afford it.
The pay is not sufficient to cover maintaining his existing residence plus live in DC as well and still support his family.
There are Congressmen who, I am speaking quite literally and seriously, sleep in their offices because they cannot afford an apartment in DC while also covering their expenses back home.
Any successful professional would -- if not taking bribes -- be taking a severe pay cut to go to Congress. Therefore few such, unless they are corrupt or power-hungry, would take the job.
That doesn't best serve the country.