#2 Sadio Mane (Liverpool) - £135.0M
Sadio Mane is one of the many top talents Liverpool have signed from Southampton in the past few years. Mane stood out like a sore thumb among the medicore players at St Mary's stadium, so it would have been easy for scouts to identify him as a target. The Reds got there before anyone else, though, and paid almost £40M for him back in the summer of 2016 - what an investment that has turned out to be!
Sadio Mane, alongside Firmino and Salah, forms perhaps the world's most formidable front three in football, and so it's no wonder why Liverpool are doing as well as they are right now.
He currently holds the record for the fastest hat-trick in Premier League history with 2 minutes and 56 seconds (in a 6-1 victory against Aston Villa in the 2014/15 season).
It's unlikely that Mane's market valuation will rise any higher than it currenly is, mainly because of his age; this is usually the part in a footballer's career where their stamina, etc, begins to decline.