    function _buy(
        IERC721 token,
        uint256 tokenId,
        address payable callTarget,
        uint96 callValue,
        bytes calldata callData,
        FixedGovernanceOpts memory governanceOpts
    )
    ...
            settledPrice_ = callValue == 0 ? totalContributions : callValue;  //**** not check totalContributions>maximumPrice****//
            if (settledPrice_ == 0) {
                // Still zero, which means no contributions.
                revert NoContributionsError();
            }
            settledPrice = settledPrice_;    
    function _buy(
        IERC721 token,
        uint256 tokenId,
        address payable callTarget,
        uint96 callValue,
        bytes calldata callData,
        FixedGovernanceOpts memory governanceOpts
    )
    ...
            settledPrice_ = callValue == 0 ? totalContributions : callValue;
            if (settledPrice_ == 0) {
                // Still zero, which means no contributions.
                revert NoContributionsError();
            }

+++         if (maximumPrice_ != 0 && settledPrice_ > maximumPrice_) {
+++                settledPrice_ = maximumPrice_;
+++         }

            settledPrice = settledPrice_;    
