I'd like to see him keep playing for us with Sarri, it's a shame he played so little last year because he's able to put in great performances. Many fans now disregard him because of last season but I think it's just a matter of starting under the right coach.
It looks like we're willing to sell him for the right offer though (€80m minimum) and if we do let him go I hope he finds the right team to shine (Spurs would be a good choice for him imo). I know it sounds stupid since he'd probably go to one of our CL rivals and I usually don't like to see players perform better for other teams than they do for us, but like many other fans I grew attached to this boy and I think he did grow attached to our shirt, too. So I really wish him the best, wherever that will be.
Oh and of course if we do let him go we should have a quality attacking replacement in line. The Lukaku rumours are just put out there to make Inter hurry up and pay ManU's asking fee I reckon (I hope).