Mikic007 what DO you pay? What company?
To go to ezeiza during the day I usually take minivan (I shared link page before). It is 45p,with one big luggage 85. It's starring close to plaza de mayo. If not, I just stop random taxi and discuss the price. Sometimes I had to ask 3 taxis to get normal price, but usually first one is OK already. Now, in Saturday night or on rainy day there might be difficult to get someone willing to take you, since they believe there is enough work around, but at the end I got always someone.
From ezeiza you just walk to departure terminal and wait that some taxi drop someone off, then you ask for the ride.
The best is if they tell you taxi meter + peaje,which happened to me in half cases and is the cheapest.
Of course, to get cheaper price you need some extra time, because if you are in hurry, you can't chase taxis around...