Unfortunately Man City, Chelsea and other clubs have fucked the transfer system value for everyone; including all the teams further down the pyramid in England and across Europe. So fees are silly, for what these players are. So unfortunately it’s the ‘going rate’ for a lot of these players. Which is why there are so many loans and free transfers done.
Certain positions you just have to pay the money. The plus points on Mendy are his goal-scoring record is consistent over the last three seasons, at Ligue 2 level, and his injury record is good.
Overall, the aim for us as a club is to get out of this league. £3m is a drop in the ocean, if it gets you £120+ for a single season in the Premier League.