I think tyou missunderstood me.
As an example let say that trainer A is a level 10 trainer offered on week 1 for $20 000, and that trainer B is offered 5 weeks later as a level 10 for $22 000. When picking those they will both have been within the same sub level of 10, e.g. 10.9. Then as soon as you pick them they start drecreasing week by week.
Let's say that they decrease with 0.1 per week. In that case trainer A would have decreased for steps at the time when trainer B is offered, i.e. even though both trainers are displayed as level 10, A is actually 10.5 and B 10.9, thus at that time B is better (even though slightly more expensive) than A.
I am not saying that this is the way it is, just that there is a possibility.