Eh, it depends, actually. Sometimes, players play more hardball than agents. I offer them a 'Relegation Release Clause', a 'Team of the Year' Bonus, and a 15 'Goal Bonus' (Non-strikers), and usually it works out alright, where I'm able to reduce players demands by quite a bit. It doesn't exactly work out, however, if multiple teams are trying for the player.
TBH, there's a lot of playing around you can do regarding negotiations and transfer offers. For e.g, I made Schalke an initial offer, plus a small amount 'After 50 Appearances' and a HUGE amount 'After 50 Goals', for Kyriakos Papadopoulous. Needless to say, they accepted. It is rather unlikely, considering he's my BWM, that he's gonna get 50 Goals.
I never include a 'Top Division Relegation Salary Drop' clause thingie, becase that doesn't help, at all. However, If by increasing their salary slightly, I'm able to get a 'Option Contract Extension' Clause, then I happily do it, depending on the players importance for me.
Point is, no contract negotiations aren't extremely idiotic yet. You'll face many cases where it's still too tough to negotiate, but most times, it should work out well.
What I hate about contract negotiations sometimes though, is the wrong information provided. 'A patient negotiator' often grows frustrated after just one re-offer, while a 'realistic negotiator' has out of the world demands..