First of all, the Prez cannot create policy by himself so any policy statements that Outgoing Prez made would require he made must have the backing of the board to be valid.

Assuming that New Prez is not going it alone in creating policy, the short answer to your question is yes, the board can do that and I see nothing unreasonable or illegal about their decision. The board has the right to manage the corporation as they see fit, regardless of the results of any petition, as long as they are within the law and the governing documents. They are also ultimately responsible for executing all contracts. Even though you say that you "already paid for them", charging back the shareholders provides a means for the corporation to recover some of the expenses of the new gates. That money is also going back into the corporation of which you are a shareholder. If the corporation needs money, the shareholders are the ones that must pay, one way or another.

Last word about the petition - a building cannot be run effectively if the shareholders think they should be involved in everyday decisions. Shareholders do not have the background information, the authority, or the fiduciary responsibilities. Be thankful that you have a board that is doing what it must to offset the corporation's expenses.