There is no set amount. You most likely will get a bill for repair to the post if it was damaged. I suggest you get an attorney ASAP to help,you with your DUI.
There are two different issues in a case like yours. First, you could receive a civil or criminal fine for hit and run (property) and also be required to pay "restitution" for repair to the property. In your case, your insurance has apparently already paid for the cost of the repair, so the concerns would be the civil or criminal violation and the possible fines associated therewith. You should consult an experienced attorney to obtain assistance with this situation.
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