Great question. I can answer that with 2 questions:
- What is the supply and demand for pilots, mechanics and engineers?
- How replaceable are the pilots, mechanics, and engineers?
From an economics perspective, if supply and demand are identical for all of these groups, a senior pilot and experienced engineer would be worth the most, then a tie between junior pilots, new engineers, and experienced mechanics, new mechanics round out the bottom of the list.
You might be asking, how do you determine replaceability? In laymen’s terms, it is the questions of “how much would it cost for us to pluck a guy off the street and get him/her to the standard of the guy we’re replacing”. A junior mechanic is relatively cheap to hire but to gain experience in a workshop and aviation setting would require an investment that costs close to an ATPL or a Bachelors in engineering. Senior pilots and experienced engineers are only available through years of experience and is very difficult to replace, this is why airlines are paying senior captains over $300 per hour of flying and large firms paying grizzled consulting engineers $500 per hour to solve their problems.