Of course you will reject a completely unreasonable offer, but 8m isn't that.
And Liverpool are playing a dangerous game.
Entriely possible they'll be stuck with a player the don't want and having to pay him millions to not play.
If no other teams were really interested in Melo it would be pretty tough to get 10m or more for him.
Marotta's position would also have been made harder if Melo has made it clear he wants to stay at Galatasary.