It doesn't cost a penny. You don't need to replace a player who has a handful of starts and hasn't played in the first team in 2018 other than brief run out a preseason.
No way. Young players who are potentially very, very good definitely need to be replaced.
You may not need to replace their performance in the immediate term. We're well stocked with Richarlison, Lookman and Onyekuru all playing down the left too, so you might not need to spend that money in the same position either.
But we do need to replace that potential *somewhere* and that does cost a pretty penny. Long term we need to be maintaining/increasing our number of under 23 players, not reducing it, and that will involve spending plenty of money. It's short-sighted not to.