I manipulate the markets to make inf, I put out bids to buy stuff cheap, then craft or resell it higher than what I paid for the item.
This does not mean I have a license to set the price of an item as high as I want for as long as I want.
I buy several of the item, perhaps even all of the item available on the market, some item which has a stable price. Then I put them back on the market at a higher price.
What happens next.
In the short term, I can simply hope buyers show up and buy my relisted items before sellers show up and list their items for less than what mine are listed for. I have to have some inkling of what people will be willing to pay to quickly get my selling price established. This needs to give me a profit, at least after a certain number of sales.
I might be able to make a quick buck that way, esp if I seed my own selling price.
In the long term, the sellers will show up and list their items. These will compete with my items in the following ways.
If they are interested in making inf quickly, they will set their asking price slightly less than the history, which is hopefully my selling price. In this case, I won't make sales, and if I buy up their items to resell or delete, it becomes harder for me to turn a profit. Sales of the item also slow down, since the price is above what was previously the stable price, the price most people were willing to pay. This causes items for sale to back up.
If they want to try and 'stick it to the markeeters' they will list the item for 5 inf. I can just buy these items and vendor them or delete them without much affect on my bottomline.
If they want to make more inf, they will set their price slightly above mine and hope it sells. This is ideal, it helps me out, its more likely than not going to be low volume, however.
They may set their price the same as mine. If I do it as a one off, it helps me, it shrinks my profits if I continue to buy and resell items because of the order in which the market sells things.
So, if the other sellers are making sales around my price, it may stick. However, arguably the price was out of wack to begin with from a supply/demand pov. Otherwise, for sale items will back up, sellers coming to the market later will see that stuff isnt moving very quickly and there is a lot for sale, and will lower the price they sell at.
So, how do I make inf 'manipulating' the market?
Low(ish) volume purchase of items at a low price, over the course of a few days/weeks, followed by resale at some higher price I've seen, over the course of another few days or weeks. I'm exploiting the flux of prices, but I can't control it on a stable item, not by myself on a long term basis.
When the prices get jacked up on previously low priced, stable things like uncommon salvage for a long time, it is because instablity has been injected, such as suddenly everyone is doing AE content and not getting salvage drops, but people still need and want those items. If you asked 100k before that destablization, you could short term buy up a lot of supply and resell and get a few "gotta have it now" sales and make some money, but keeping the price up there in the face of that much supply would just keep raising the price you have to pay to make the 100k sales by buying up the incoming sales until you couldnt make a profit, and then the price would collapse.