If your cost-benefit analysis works for you, that's great.
I have not used better than Advanced trainers, and I have never bid more than $30K to win one. Generally I'm getting a guy with salary between 11,500 and 12,500. I keep them until they get to around 16,500. At that point, saving another 4-5K per week ends up being worth spending about 40K in bidding and severance. After about 8 weeks, it's savings for another season or so.
Unless I were trying train at the NT level, I can't imagine it would be worth the extra investment on a trainer for me. I'm not even sure I can justify my costs of scouting and training as it is. Sometimes I think it's a losing game entirely. I can easily spend 300K on scouting alone and not be able to recoup that from selling the draftee, and calculating the eventual Merch benefit from keeping my guy is beyond my ability at this point.