It's not so much the cost of the engineer but the reduced costs of the others, in this case the dockyard workers. When I was at ASTA they employed ex car workers etc, some basic training, and away they went. When I was at BAMC they employed ex mine and car workers, some training and away they went.
The basic engineering skills were there, with some specific training they were let loose on a/c under the supervision of the engineers. Of course these people were employed on a lot less than the experienced mechanic/technician. So the cost base was reduced.
Don't get me wrong some of these guys were very skilled indeed. Those that weren't were in the seat shop etc.
So is the cost of an engineer proportional to the safety level, quite possibly only time and a few major incidents will tell.
Would I be willing to compromise on safety, absolutely not and never will or have done knowingly. I've made mistakes of course as I am human, and you learn from them.