§ 223. Expense of improvement. The expense of any public improvement made under authority of this article, shall include the amount of all contracts, the costs of all lands and interests therein necessarily acquired, printing, publishing, interest on loans, legal and engineering services and all other expenses incurred or occasioned by reason of the improvement or project. In no event shall any contract be awarded or obligation incurred in excess of the amount specified in the resolution of the town board or in the proposition adopted at the town election.