You can't just use inflation as a measure of previous fees and current. Things like revenue also need to be taken into account.https://www.bankofengland.co.uk/monetary-policy/inflation/inflation-calculator
If you factor in inflation these amounts would be:
Figo, 2000, 37m would equal 61.1m GBP in 2018.
Zidane, 2001, 46m would equal 74.7m GBP in 2018.
Also, for reference:
Beckham's 2003 transfer for 25m would be 38.8m in 2018.
For example:
Zidane for 46m was 38% of their total revenue for 2001-02
Pogba for 98m was 15% of our total revenue for 2016-17