isn't this the biggest and toughest part?
These days I don't think so. If the player is keen to join you, and you have our chequebook then you're 80% of the way there. Once you've got the agent onside, you get to the point where the club starts weighing up what their price is.
If the price is at all sensible, it's just a case of bartering and posturing until the clubs agree.
IF the price isn't sensible then the agent starts causing problems (knowing that his pay day is dependent on it) and then clubs start wondering if all this trouble is worth it.