In aviation professional flight crew licenceing, training, type conversions and so on, bonding for a period of time has been the norm. This has abusivley disintegrated in the hands of some operators to paying for a position as a first officer. The rationale behind this perhaps equates with an articled clerk who is employed at a low wage while he gains sufficient experience to be able to put the cherished letters behind his name-in other words, have gained the experience to be able to go it alone.
The system has been seriously abused by operators recently, all over the world, taking advantage of the masses of young people whoo wish to fly but have no concept of the competition of the market. A market too, which is extremely susceptible to economic conditions.
If, as in this case, the company would appear to be recouping the costs of training out of wages, then that approach is nothing new., It may have the advantage for the person paying in that he might find himself in a lower income tax bracket. Had he paid for his training up front, he would have been unlikely to have the advantage of any tax deduction benefit. I notice that the equally experienced but not 'in house' trained candidate is not receiving any preferential treatment on the seniority ladder.
As long as the training deductions are reasonable both as to amount and to deducting period, I cannot see too much in the first post that is out of the ordinary, unfair or even that cannot work to the poster's advantage.
PS: As a cadet for a certain airline, he should be damned graetful he is one, should put his head down and make the best of an opportunity for which many would willingly assassinate him.