Having recently been unsuccesful at interview stage, I would have gladly paid (within budget) to have someone help me through the process ie interview skills. Granted that the aptitude test etc cannot be prepared for, the selection process makes it practically impossible for an applicant to be succesful if they have all the knowledge/aptitude/IQ needed but are awful at interviews.
Not suggesting that I'm the next Einstein but for someone like myself who knows the answers and what they want to say but just simply cannot put it into words that an interviewer (or anyone else for that matter) would understand!
In hindsight, if I could have had some mock interviews to help me with my known weakness, even if I had to pay for them I would have done it in order to succeed in a very desirable career.
P.S. Congrats Billy!