When I was in the army, I went on temporary duty (TDY) a few times - once to Knox and once to Benning.
We got a housing allowance - up to $39 per day.
Guess what all the hotels in the area charged?
Unintended consequences.
I'm currently TDY for over 90 days. That puts me into a 3/4 per diem situation. Guess what? All of the hotels have enough customers on less than 90 day TDYs...with full per diem.
I can't find ANYTHING at the 3/4 rate.