Don't think it's going to affect price much, especially now when JS/JR also affects your player's FTs.
For me, I maxed out my training court coz I'm training NT players. With a maxed out training court, a player would probably pop two to three times a season, so if you start at 1 (worst case scenario) you'd have him be around 12-13 by the time he enters his 23 y/o season. Seem pretty good, but I doubt people would pay a premium for that. Also, you'll have to factor in maintenance cost as well, I think it's 15k a week. One season should be around 14 weeks. That's around 210k a season. Would you be able to recoup that amount?