Honestly, the REPORTED purchase option seems very high however if he can establish himself as a great midfielder then it's worth the price to pay to have a great engine midfielder who is 21. If he does not establish himself, it's an expensive loan that we walk away from at the end.
I consider the high-ish loan fee to be the cost of trying him out. Giuntoli loves him and always wanted him and now he's got 5 months to prove to us he's got the makings of a top midfielder. Obviously, we'd love to buy the next Vidal for 15m again. But maybe this time the next Vidal costs us 50m. If he truly is that elite level, is the transfer price the best? No, we would've always wanted lower. We want lower transfer fees for all good players, I'm assuming. But if he can be that level of a player, I'd pay it. Hindsight is 20/20, we don't have a crystal ball. But damn does it seem expensive right now.
Time will tell, we've got five months to figure out how we like him. Looking back at how he's developed, I would've bid 50m for Camavinga when he went to Madrid for 31m. We won't know if its worth it until we're already passed it. But a massive gamble from Giuntoli.