Well.... the currency that's important to you is EC, for those hundreds of millions of EC costing ships.. 100 Zen buys you 1 key that's worth a semi-astronomical 5 million EC (on PC..) (for *1* key!). Soooo if console key prices are similar and you get 10 million EC out of your 1 key I'd say your flip mastery skills have triumphed once again : )
The same with any MMO, there are three levels of selling loot. (Example: 4 million avg. sale price for a Master Key on the Exchange)
Short the Average Price -- You take a hit on the sale by undercutting the lowest price and selling it for less than everyone else. (Sell your Master Key for 3.75 mil EC...) However, you can turn out a sale in minutes. Great when you have a quantity of items and looking to turn over quickly.
Set a Fair Price -- You price your item the same as everyone else. (Sell yours for 4 million or a little higher, maybe 4.25.) When demand gets short and someone needs a quantity of items at any price, that's when you make the sale, but it'll take a few hours, maybe a day.
Go for Full Price -- You set a price on an item that costs more than a typical sale. (Sell the key for 5 mil EC.) Here, you'll wait a few days before it clears. If you only have one item to sell and time isn't an issue, this may be your best tactic if you need a specific amount. THAT, and you've done enough homework to know this is where the average price CAN hit when demand increases.
There's a fourth approach, but it doesn't work very well...
How does I Exchange? LULZ If you are unreasonable with your price, (Want key? 12,000,000 EC) then no one will buy it and the Exchange will return your listing unpurchased in 72 hours. You're free to relist it for that much, of course, but it's wasted time.
This also happens with items that are 1-5 in quantity listed on the Exchange, so folks set the price to something ridiculous (the Exchange ceiling is 1.5 billion EC), then when it fails to sell, come down from that incrementally until a sale does happen. Slightly more reasonable, but a lot of work to clinch a sale, for example, that recent Tier 6 Escort drop from an R&D Sale event that just ended recently. Price? 1 billion EC. But it's still gouging. ("Because of scarcity, they'll pay what I ask" only works when folks have that many ECs to toss on such a thing, and to be honest, EC is simply not as useful in large quantities as Dil or Zen.)