Fiduciary duty may not require directors to choose open-weight models, but it should make it increasingly uncomfortable for them to approve material proprietary-model spending without knowing whether open alternatives can perform the same work for less. Now that credible open-weight alternatives offer material savings, greater data control or reduced vendor concentration, that process should normally include comparative benchmarking and total-cost analysis. As AI spend becomes material and credible alternatives offer potentially order-of-magnitude savings or materially different security and dependency risks, the duty-of-care expectation of an informed process increasingly supports a documented alternatives analysis.