More broadly, I am just pointing out that its really hard to RuneScape gold'hide' an artificial restriction (at least one that produces an important impact) on a market if there's sufficient data readily available on the industry. Demand curves and product costs are revealing on stuff like that. There might be workarounds, like obfuscating by having a list of items instead of just one which are randomly selected or randomly jumped around. However, it would definitely be a problem for OP's design if executed word.
Make it an occurance that happens at the close of the dump. If in the end 10billion is tossed afterward the correlating GE earnings of this random unknown thing are subsequently bought out. No telling of it happening in any way. No opportunity for abuse. To minimize abuse potential even further I would also suggest making the buyouts happen at random intervals, to prevent people from only stockpiling random items and then posting them at 9.9percent over market place before the buyout occurs. So if the buyouts are arbitrary its still possible to do so, but you'd be sacrificing all your GE slots to have items sitting there all the time so it would be a gamble.
This is really difficult to'hide' from players, as sink tems could be recognized almost instantly via aggregated GE data. It would be pretty straightforward to develop an automatic version to predict/identify them based on materials like price swings and trade volume. And identification fully anticipate if this were to go as suggested websites like'getracker' would add a tool on their front page suggesting that these items.Why do you assume the items are being purchased as the gp comes from or they simply would not show trades completed this way as a portion of their trading volume considering its not.
It would not be hard to hide at all if they wanted to, there's an insane number of ways to accomplish that. Just because there's ways under your premises around it doesn't make your assumptions correct. I mean the things are purchased from RuneScape 2007 gold somebody right? Sell offers are being stuffed? I might be wrong on this but my premise is that the ge tracker sites take information from apps like runelite, or at least in certain way that isn't data given directly from jagex. You're correct they could hide it if all data on sell/buy provides is obtained straight from some API jagex has immediate control over, and there is no other means of receiving it from users, but I do not think that's the situation.