Hair tests might be expensive but they are not extremely rare. Maybe at the initial interview stage but not for final acceptance stage. My friend's daughter was hired for an executive entrance position in the energy industry by Conoco. As part of her final acceptance stuff she was given a hair test. She was clean but had vicodin showing because she had been to a dentist. She had to get a letter from the dentist and the pharmacy records. And someone above mentioned government jobs too as giving a hair test. I think certain employer segments will spend the money on hair tests as a final condition for acceptance. Especially for medium to upper level jobs in which they plan to invest a lot in the future employee and hope to retain them for a while. In your situation, I would not worry though, given the amounts and the timing. I am certainly not an expert though.