Walker was 27 when he left. Pulisic's resume is pretty much the exact same as gordon's. Again Pulisic wasn't even starting and Dortmund held until they got the price they wanted.
More than 1 club w/ money to burn likes him. His salary is reasonable, we probably really gonna need him this year so if he stays, fine, he'll hold his value until Jan, probably despite the contract until the summer. Monied clubs always pay in the end an extra 15-20M is a drop in the bucket to them. LC stuck to their eval of Mahrez and rebuffed the 70M Man City offer, even tho there were less clubs that could afford a Mahrez, not to mention that Mahrez was more of luxury player that Man City didn't really need and still in the end Man City paid up.