However, the benefits of such a fellowship, scholarship, or grant may be accepted by the member in addition to the member’s pay and allowances only to the extent that those benefits would be conferred upon the member if the education or training contemplated by that fellowship, scholarship, or grant were provided at the expense of the United States. In addition, if such a benefit, in cash or in kind, is for travel, subsistence, or other expenses, an appropriate reduction shall be made from any payment that is made for the same purpose to the member by the United States incident to the member’s acceptance of the fellowship, scholarship, or grant.