Even at 100m, it would be a good buy IMO (especially considering that we can get some money back by selling 2 out of Jones/Rojo/Bailly). He will instantly improve our defense. Also, let's not forget that we didn't spend too much last season, so we should have some money to spend. Additionally, it is hardly that we need improvements in many positions. Get Koulibaly, a right-wing attacker and possibly a right back and we are set to go.
A deep playmaker would be ideal too, that's just me being greedy though, I guess.