Not enough!
A friend of my wife had huge discounts on Agoda simply because of stacking, many offers ONLY stack, you cannot turn the stacking feature off for them.
Scour through YCS, turn EVERY discount, promotion and scheme off.
The worst ones are Agodas own schemes, "AGX" etc., bin the lot and start again.
Remember Agoda also charges higher commission than the other OTAs, typically 5% higher for this part of the world.