Advice bidding industry mining sites

[All seasons festus]

Hello I'm looking for advice on bidding some mine sites it's the roadways entering the mine. I will have to get emshea lisence which are a added cost and up my insurance policy. My questions is is there a certain rate for this type of work. Don't want to under bid are over bid. My current rate is 40. An arce for properties more then 3 arces. Any thoughts would be greatly appreciated. Thank you. John. All seasons