Some tricks to using the Grand Extortion:

[Doomedrusher]

These are just some tricks I have found, please post your own strategies if they weren't mentioned.
-Unless you are desperate to sell an item or if 90% of RS is selling for minimum, don't leave the item at minimum price overnight. Get it out of the ge and list it again at market price tomorrow to see if there are any buyers for that item at more than average.
-If you want to sell an item at market price but others are listing it for market as well, put it 1 coin below the market. This way your offer gets executed before everyone else's.
-Similarly, buying for 1 coin above the minimum will ensure your offer is favored more than others' in an item selling for minimum price.
-Don't be the first person in a transaction. The GE favors the second party, regardless of their role. I always leave my GE empty and list the items I want sold temporarily. (This rule does not apply to large volume items, such as coal, feathers, or fire runes.)
-An item dropping in price means that you can always buy it on the ge if you list a buying offer.
-An item rising in price means it's an instant-sell.

[ikraz55]

Interesting. For expensive items, I list my prices 20 gp below market instead of just 1 gp. That way you undercut the people who are trying to undercut others

[Doomedrusher]

NO! You revealed my trump card!

[Craven Range]

Interesting. For expensive items, I list my prices 20 gp below market instead of just 1 gp. That way you undercut the people who are trying to undercut others

People tend to like round figures. Therefore i go to the nearest round figure, say 2,000,000 and add 20 coins, to make it 2,000,020.. works well

[ikraz55]

AHA! my real secret is that i add 21 gp. PWNT....

Wait.. (oops)

[G Bub]

I'd like to bid $1 Bob.

- G Bub

[kiwi db]

Interesting. For expensive items, I list my prices 20 gp below market instead of just 1 gp. That way you undercut the people who are trying to undercut others

Soooo, let me get this straight. You undercut those people who are already undercutting . Sounds like you are trying to be one of the masses rather than the BRILLIANT individual - then again, sometimes the masses are more brilliant than the individual

[Heleor]

I'm probably one of the worst players for the economy: I always buy for maximum and sell for minimum. The reason for that is that I dislike waiting, and I know that it doesn't work as well, but I can't help it.

[Lady Lisa]

Interesting. For expensive items, I list my prices 20 gp below market instead of just 1 gp. That way you undercut the people who are trying to undercut others

I use this tactic a lot. It comes from my time on eBay. I have the number 8 in my user name so when I make bids I use it. $10.08. Works like a charm.