(a) Except as authorized in this section, no person employed by the U.S. Government in Indian Affairs may have any interest in any trade with an Indian or an Indian organization. Employees of the U.S. Government may trade with an Indian or Indian organization for any purpose other than to engage in a profit-making activity under the following conditions:

(1) Where the amount involved is $500 or less a U.S. Government employee may purchase goods or services from an Indian or Indian organization.

(2) Where the amount involved is greater than $500 a U.S. Government employee may, with the approval of the Secretary of the Interior, purchase goods or services from any Indian or Indian organization.

(b) Lease or sale of home sites or allotments on trust or restricted Indian land to or from Indian employees of the U.S. Government shall be made on sealed bids, unless the Commissioner waives this requirement on the basis of a report showing:

(1) The need for the transaction,

(2) The benefits accruing to both parties, and

(3) That the consideration for the proposed transaction is not less than the appraised value of the land or leasehold interest unless the Indian employee qualifies and is intending a transaction in accordance with § 152.5 (b) and (c) of this chapter or § 162.5(b)(1), (2) and (3) of this chapter.

(c) This section does not prohibit any reservation business from contracting with the Federal Government to provide postal services to Indian communities in which Government postal service is unavailable.

(d) Nothing in this section prohibits an Indian employee from receiving benefits by reason of membership in a tribe or corporation or cooperative association organized by and operated for Indians.

(e) U.S. Government employees who violate this section are liable to a penalty of five thousand dollars ($5,000) and shall be removed from office, see 25 U.S.C. 68.