Notice shall be posted inviting sealed proposals or bids for doing such work, or for furnishing materials, supplies and equipment or any portion thereof. Notice inviting such proposals, and referring to the specifications on file, shall be published, but if there is no newspaper published in the city, then it shall only be posted. The time fixed for the opening of the bids shall be not less than 10 days from the time of the first publication or posting of the notice.
Said notices shall state the estimated cost of any acquisition, which estimated cost is required to be advanced as a part of the incidental expenses referred to in Section 5256 of the Streets and Highways Code, at the time of entering into the contract.