90% of the time its talking about primarily the weekly wage, sometimes it will be 50k a week a 2k appearance fee and a 4k goal bonus, sometimes it will be a flat 54k and average out to the same thing. The way a wage is made up isn't particularly important, it will be when a player wants 50k and the club won't go beyond 30k that things break down.
99% of breakdowns in deals are when a player wants more than the club is offering and the club won't be negotiated higher.
I'm almost certain that Pienaar's deal failed because he wanted a LOT more money than they thought a backup midfielder was worth.