I understand this is just an opinion, but I don't think it corresponds to objective reality. Certainly not for January.
For someone to become a bargain it means either the club want to push them out, or the player is pushing to leave. None of those apply here. There are 0 noises from Juve or the player that they want to part ways, be it for financial or sporting reasons.
After a very poor start in the league, they started hitting form (6 wins on the trot) and they've managed to sneak into the top 4 by a mere point ahead of Inter. They would not sell their main goal threat mid-season. That would be very likely to cost them the top 4 and UCL football next season. Needless to say, that's hugely valuable to them for financial and reputational reasons. On top of that if anyone is more desperate for this transfer, it'd be us not them. It's us who are left with only 1 injury prone striker for the rest of the season. So why would they throw us a mid-season bargain? They would be far more likely to try and fleece us for every single penny.
On top of that, people forget that when Vlahovic was leaving Fiorentina, the only club he wanted to go to was Juve (
Sky Sports | Vlahovic only wanted move to Juventus). There has been 0 noise from the player's camp that he is disgruntled and wants to leave. Even if Juve were ok with striking a deal, it's highly unlikely he wants to come here and frankly what for? Juve offer UCL every year. They won the title 3 times in the last 5 seasons. We've not been in a title race in nearly a decade. The only thing we can perhaps offer more, is money. We'd be in another Dybala/Rabiot situation where we try to lure a player that doesn't want to come with a high salary. Far from ideal.
In either case, if this transfer were to happen mid-season it would cost a helluva lot in fees and salaries. And for this to happen in the summer, Juve would have to finish outside the top 4 and we'd have to finish in it.