Suarez has a first team wage now, not a Barca B wage. Clubs that request to loan a player usually also pay a loan fee in addition to paying the wages when they loan the player.
Still don't have costs (I mean, additional costs).
I rather loan for free to Sevilla than for money to Aston Villa or any other EPL shit team.
We can't add Suarez official fee to Rakitic signing fee. In fact, if Sevilla choose to buy him, we need to subtract his fee from Rakitic.
Suarez returning: Raki cost us 18M;
Suarez not returning: Raki cost us 12M.
You could argue, of course, if Suarez worth only 6M and if we made the right call. But we just don't know yet.
I think he will never make it to be Barça first team level, although I like his style.