Big wages that its easiest to offer to the out of contract players this coming summer, then the typical big transfer fee+salary combination.
Yes, but in theory we could spend 20m eur total (transfer fee+wages) and bring 2 top players.
Lets say we sign Tevez 1 and Tevez 2. Both players cost 25m eur and want 6m eur for wages. That's 50m eur + 20.6m for year's wages (tax included). Total = 70.6m eur.
We're bringing 2 attacking players for 70.6m eur.
We need space for those two attacking players now:
Iaquinta, Amauri, Grosso, Toni and DP (if contract won't be signed) will leave for 0 eur but free up 21.5m eur wages.
Quag and Krasic are sold for 20m eur total. Their wages are 6.55m eur total, tax included.
21.5m+20m+6.55m = 48m eur.
70.6-48 = cca 22.5m eur.
So we get rid of players we don't even use on the bench anymore (Amauri, Toni, Iaq, Grosso, Krasic) and two bench players (DP, Quag) and replace them with two top strikers (in our case called Tevez 1 and Tevez 2) with all of that costing us only some 22m eur (transfer fee+wages).
Looks nice in theory and it's hard to be done in reality. It was just an example to show how with little money we can make the team too much stronger by adding class players to replace players who hardly get to play or don't get to play at all.