Alright, time for Sophus' rant.
Choky is 100% correct. The fact that "gil sellers" camp this item has nothing to do with the price. Unless they are using programs so that *no one* else but them can get it (which isn't the case), the people responsible for the increase in price is us. The O.Kote is only going to cost what people are willing to pay for it.
Even if 5-10 people opt not to buy it, the overall effect on the price of the item will be nil. The way I see it, you only have 1 of 2 options to lower the price w/o SE intervention:
1) Decrease Demand
2) Increase Supply
The way to decrease demand is simple: camp it yourself. It's not impossible to get (AGM got 2 in one day not that long ago if I remember correctly). If you get it, you don't need to buy it. If no one needs to buy it, the price will go down.
The way to increase supply is...well...a little more complicated.
On the surface, there's only one source for the kote: Mee Degee the Punisher. In actuality, there's 3 sources: the nm, the ah, and the players that already have it.
Now, the players who have it probably won't want to sell it. And if you're camping the item yourself, you probably wouldn't want to sell it either. The only option left would be to buy one off the ah (or use your own if you're feeling really lucky--or vindictive) and manipulate the market.
Basically you'll have to get about 5-10 people and pick a random time and day to wipe the ah history. Someone would need to put up an O.Kote for a lower (but not unreasonable) price. The current price is 5mil? Put it up for 4mil at first. Then have everyone buy it before someone else gets it. Do a couple of transactions like that.
After a few rounds, new people wanting to sell their o.kotes will see the price going down and try to undercut to sell theirs first. Eventually what you "create" is a lower price due to a perceived increase of supply. In actuality, the supply has only increase by 1.
The "gil sellers" who stuck their kotes for 5mil will have to stop their sale and relist their items since the price has dropped over a million. That not only costs them the original AH fees, but the fees of relisting it as well. They'll have to do it, though, because any drop in price is a hit to their quota. It's also guaranteed that they won't relist it at 5mil any time soon since the tax on 5mil adds up.
That method will cost you a good chunk of change. You'll need an initial O.Kote, as well as all ah fees and people with enough money to buy it. When you're done with it, you will have also lowered the value of your O.Kote. However, I guarantee it'll start a lowering trend.
The trick would be to a) make sure someone outside doesn't buy it (space them out over the day) b) don't have the same person who bought it sell it that day (a savvy buyer can smell those scams a mile away) and c) try to clear the AH history so no one knows what the original price was.
This has been a lesson in evil economic manipulation by your good pal, SophusTehNewb.