He's a likeable little player, but I think he's just had a fantastic season playing for a very good team. I don't see an undeniably world class player. He's very good, but the amount of goals he's scored has perhaps disguised more than a few average matches.
I think Liverpool would expect Coutinho money, but he's worth no more than 70 million at this moment. This time next year, if he's continued to improve and has banged in another 30+ goals there'll be a few teams circling with that 150 million ready. And fair enough - he'll have proved himself to be world class.