I did a lot of interviews via GLG (and similar services) as a consultant, with rates ranging from $200-700 per hour. The $700 range was for C-suite interviews at $5-10B revenue companies. I imagine a senior person at Apple or Boeing would be well in the thousands per hour for a similar service.
The people who are paying for these services aren't small start-ups trying to grow -- it is private equity and consulting firms with really deep pockets making multi-million/billion dollar decisions. They'll pay what it takes.
I've done GLG (and other similar services) in the $700 range. It's not just for C-level execs at $5-10B revenue companies (I cofounded two venture-backed startups).
I started by charging $400. Then I realized that some of these calls last 15 minutes. At "$700 per hour" we're talking about a whopping $175 to do the scheduling routine (some back-and-forth), make time in my schedule, interrupt "flow", and take the call.
I now insist on a 1 hr minimum and bill $700 and do it occasionally when the offers come in (handful of times per year) because I like talking about the subject matter. It's not exactly the best use of my time.
i would like to speak to a similar group, except 20 years more mature, running a business like Apple or Boeing.