Usually these are quite simple, i.e: a bid over x and we have to let Suarez + agent know. Any less and it can be f***ed off out of hand. I believe they are quite common.
One thing that is of note is how we've faired against the top sides, we seem to draw 2-2 against them after having the the better of them. We seem to be 1 player away from achieving that balance without taking too much from attack.