well, two of hrudey's trainees were sold for $450K; one was purchased for 55K, the other for 10K.
So, call it 850K net on just those two guys.
If he trained those guys for 4 seasons, and the average trainer cost was 20K, that's 1.12 million for the trainer.
That leaves him down just 270K, meaning whatever other players who got trained in that time period only have to be worth that much to break even on trainer cost. I'd guess that Menard and Wray (who were contemporaneously trained) would likely sell for similar amounts at Newton and Tuozzi. If so, his training program created 4*425K - 1.12 = 580K.
Now, that's not to say that training is a way to make huge amounts of money. You have to train well and create well built players. But you have to do that whether you train high potential, pricey trainees, or cheaper low potential trainees. And yes, there will be times you put out a substandard lineup, and lose some games you could have won. But as hrudey points out, there's also the fact that as the season progresses, your trainees perform better than the salary you pay them.
In the end, your assertion about the TL worth of well-trained, low potential players was wrong a couple of seasons ago when we had this exact same discussion, and is even more wrong now, given the rise in the market (following the change in free agent criteria).