I don't know about pilots, but as a licensed maintenance engineer I think I can have "Tech Eng. CEI" if I pay some money to someone, but I don't see the point. I'd rather spend it on beer.
As a Flight Engineer in a former life I was told by the aircrew manager that a new post of "Senior Flight Engineer" had been created. I asked how much more money? I was told that there was no more money but I could wear 3 stripes instead of 2. I told him to shove it where the sun doesn't shine!
I did wear the 3 stripes though, (with the Royal Purple) and was always amused in the Middle East to be called Captain by most of the ground staff.