My question involves labor and employment law for the state of: Arizona

A student was offered a job via email and confirmed through expressed mail for 90k a year. The employer ment to offer him 60k/year and after realizing the mistake revoked the offer. This was only after the student turned down the other job offers he had and purchased $5,000 in new suits and work related material for this new position he believed he had. The student now wants to hold the employer to the offer and work for the company. If he cant keep the job he wants the employer to reimburse his for his expenses (he cant return the clothing and material).

Does the student have a valid offer from the company?
Was there a valid acceptance?

What can the student do to hold the company accountable?
What can the potential employer do?