Who was supposed to approve it? Nobody; he's Head of Department, as they're called tin the Appointments Clause.
What he WAS supposed to do was report expenditures greater than $5,000, which he did. He was also expected not to go crazy, though that is not a specific instruction.
People should have known what to expect. Do you remember those photos of his one-time house in Maryland? He's in love with luxury. And himself.