Last few years Chelsea done great things on transfer market and in lot of cases bought good players for good price. Torres was last player they overpaid. Hazard maybe a bit too but his quality and age cancel that.
Luiz, Cahill, Azpilixxx, Ramires, Oscar, Moses, Hazard, Ba, Marin, Mata, De Bryne, Lukaku, Atletico goalkeeper..
All great signings and some of them very cheap for team with their spending reputation. And all young players that will serve them for many years. Marin is only transfer I don't understand, never stood a chance to take a place in that team.
We can say this or that but their scouting and transfer targets were almost perfect in last few years, best in England and could only be challenged by king of transfer market Milan's Galliani.