In Devarim 17:8-9 we read:
If there arise a matter hidden from thee in judgment, between blood and blood, between verdict and verdict, and between plague and plague, even matters of controversy within thy gates; then shalt thou arise, and get thee up unto the place which the LORD thy God shall choose. And thou shall come unto the Kohen the Levites, and unto the judge that shall be in those days; and thou shalt inquire; and they shall declare unto thee the sentence of judgment.
and then again in pasuk 12:
And the man that doeth presumptuously, in not hearkening unto the Kohen that stands to minister there before the LORD thy God, or unto the judge, even that man shall die; and thou shalt exterminate the evil from Israel.
My question in why are we talking about Kohanim? The sedra is called Shoftim. The point of the pasukim we quoted is that if your local shofet can't answer a question you should go to the sanherin and ask them. At no point does the torah mean to imply that you should be asking a local kohen you find in the temple to adjudicate your monetary questions.
So why are we bringing the kohanim into the picture here?