You can also take it the other way round :
high prices favour the teams training players with the purpose of selling them.
1) Training is made much more easier in lower divisions. This is pretty self-explanatory, I won't explain further.
2) Replacing a player in a top division means you basically need a top player, thus extremely expensive, whereas a lower recruit aht the thirs of the price would be enough in D.2
3) Training slots are scarce in BBBL because you have to win games in order to stay in BBBL. Meaning you sometimes have to let a spot slip, thus making training much worse than it would be.
4) Some teams aiming at trophies don't even train at all and train GS all season long.
The plan you're talking about, you weren't the only one thinking about. It doesn't work. You have to find another way to success. That's what Joe did, Amenra also, and probably this season Nat.
I am training player,s I've always been. And although I should "rejoice" at these crazy prices, I'm not.