Except as otherwise provided in this part, the Director is authorized to conduct or make grants and contracts for, or both, programs to carry out the purposes of this part in accordance with the authorities and subject to the restrictions in the provisions of part A of this subchapter, except for the provisions of sections 4953 (f)1 and 4954 (d) of this title, and except that the Director may, in accordance with regulations the Director shall prescribe, determine to reduce or eliminate the stipend for volunteers serving under this part on the basis of the value of benefits provided such volunteers by the institution in question (including the reduction or waiver of tuition).