i just think that getting level 6 or 7 trainers doesnt really necessarily proves you should be getting more gains than your cost.
as what im tried to say earlier, and try to change it a bit probably if you want to get from location A to location B which travel "X" miles . . .
now if you have a level 5 or i say 1.6 valve car, you will consume "Y" liters of gas at lets say "Z" miles/hr
but if you have a level 6 or 7 for lets say 2.0 valve car, you will consume probably more "Y" liters of gas at a more "Z" miles /hr speed rate.
now if we put it into a more perspective, usually on a free way i probably would say you would get early by just half an hour or an hour or even a few hours earlier but it wont make a big difference for you to say that the gas you consume could really justify the time you got their early.
but to sum it up you got their earlier than a normal car or 1.6 valve car :D but surely you consumption or cost is way more.
now going back to bb universe, i do believe the bb's would do it in the sense that it will save you from turning your team from being a talent or player skill developer in a span of quick time wherein you can keep that trainer with heavy cost but you can sell players to help you.
i agree with superfly here, its still a long term thing but you just got a little ahead of everyone:D