#2 Alisson - £56.25m

It was Manchester City who initially had the best chance of signing Alisson, but their bid of £34.7m in the summer of 2017 was ultimately rejected, as it was considered far too low. After City turned their attention elsewhere, Liverpool crept in and managed to swiftly wrap up a deal the following summer.
The cost of the transfer has been largely shrouded in conjecture and speculation. Transfermarkt report the fee to be around £56.25m, whereas other sports news outlets spout figures between £55m and £70m. As the figures in this article are all from Transfermarkt, we shall take their valuation as the truth, as they tend to be the most accurate with these things.
Alisson is a great signing for the Reds, especially with the recent comedy of errors from both Simon Mignolet and Loris Karius. It's about time they brought in somebody consistent.