I think we're absolutely fine.
Instead of going for a foreign player who will have an adaptation period, if there's no one we want from the PL, then we are surely 80% there with Romero. Romero with Grant and Henderson as backup is fine for my liking.
Besides, and perhaps more importantly, we'll need that chunk of money for other more pressing areas of the team. No point in blasting nigh on 100mill, perhaps 35-50% of our overall budget on a GK when we have a settled and ready to go Argentinian No.1. That money will be better spent on CB/RM/RB/DM/CM/ST if Lukaku goes.