Any sale or encumbrance to the personal representative, the personal representative's spouse, agent, or attorney, or any corporation or trust in which the personal representative has a substantial beneficial interest, or any transaction which is affected by a substantial conflict of interest on the part of the personal representative, is voidable by any person interested in the estate except one who has consented after fair disclosure, unless
(1) the will or a contract entered into by the decedent expressly authorized the transaction; or
(2) the transaction is approved by the court after notice to interested persons.