Let's do the math,
5X25k=125k
few seasons.... (lets say 3)
lets say you pay 10k a week for that trainer (generous, you prolly still pay around 15k all told)
10kX14X3= 420k
You can quantify the cost of losing more games, because 5 30+ yearold players bought for 25k have waaay more skills plus experience, you can also STILL TRAIN their FT and ST for free which comes with pops now and trains ALL your players, not to mention you can train GS which will allow you to keep a smaller roster and perform better at eveyr position, not just improve 5 players.
I'll be generous and not make you pay for lowered performance in this caluclation.
That is awful generous of you. I am curious how many fewer losses you think I would be capable of having with your strategy; if it turns out I could be 19 - (-4) right now, for example, I'll kick myself for being such a fool.
Now lets look at pops. With OD, level 4 trainer, not ideal height, guys that have holes to begin with, maybe not ideal height, two position (c'mjon you are claiming you can get this guys for 25k each).....
You are gonna get about 2~3 OD pops a season if you devote to OD training ONLY. Lets say you start at about 10 OD pops each. Oh wait, STAR potential???? Well they could have 16 OD and NOTHING else. hansome roleplayers that a top team might throw on his bench for emergencies/to fill out uncritical games against tanking opponents.
The 25k is more of an average. If you prefer, you could spend less initially, and then upgrade -- I had a guy I bought for 1k, trained for a season (and was a quite useful player in V), sold for 75k. Another was a FA buy in single digits and after about 2 months sold for just under 150k. But I also have a guy that I bought at 10k who is still on my club and plays regularly.
But, yeah, I imagine I've done a lot more shopping for star potential 18 yo guards in my time than you have. The really good ones of course will have a higher purchase point, but if you're willing to take on an inept here or there, it's quite reasonable, especially when you're more concerned with height and with getting good skills rather than the ultra-top-end ones.
Perhaps with the new rules though the amount of value you can get out of training stars will increase a bit, maybe they'll be worth a bit more than 10X salary, maybe. Consider if you trained 3 seasons you paid the salary 36 times...so I hope he contributed what his salary cost compared to a cheap 30y/o with experience. In that case training and daytrading, together, whilst building the arena and finding a way to promote is tops approach.
If you replace trainees with old players, you still have to pay the salary. And if you get higher skilled ones, as you seemed to advocate, you're just paying higher salaries each week. Oh, sure, maybe you then go with a few less players and save some of the difference there, but that's fraught with it's own troubles. Heck, just the difference in merchandise between my team and the league average just about covers the cost of the two most expensive trainees right now -- you can't say that when you're turning over players left and right, certainly.
The long and short of it (more long, obviously!) is that it is quite possible to build a team that focuses on training, even two position training, and that is successful and quite profitable at the lower levels of the USA. Perhaps higher up that strategy wouldn't work (and I'm already switching to one position now for the first time in my BB career), but in V and IV, in my experience, it's quite adequate indeed.