@ Motherland - You made statements about "The FC responsible" and "The FC is given a mandate".
That thread is open to all posters and FCs. There has never been any FC that Jagex has declared or mandated is responsible to maintain price ranges. There are no forum or game rules about how any price check FC has to determine ranges. The FCs each set their own rules for what is acceptable behavior (within the Rules of the Game of course) in the FC.
It is not the responsibility of Forum Mods to check to see if posts on a price checking thread, made from any FC, are following the in-game rules that FC has set up for it's members and ranks. It is up to the owners and ranks of each FC to enforce that FC's rules, not the F Mod team.
The F Mods' responsibility is to ensure the Forums remain fun and safe. And if we see things on the forums that are disruptive or break the rules of the game or the forums, we have the ability to take action on that. F Mods are normal players, and have no access to any trade histories except our own. We cannot verify if any of the trades reported on that thread actually took place for the amounts reported, and we should not need to.
The stated purpose of that thread is "to keep track of a
rough
idea of all discontinued item prices". The key word being "rough". It was never intended to be an official and completely accurate trade log. And there is no way that it can be, because there is no requirement anywhere that every player who trades a rare item must report it on a forum thread or to a specific FC. F Mods can and will remove any obvious attempts of price manipulation on the forums. However it is not our place to dictate to any FC how to determine their price ranges.
If you have concerns with the way a particular FCs ranks or members are calculating or reporting price ranges, that is best resolved by discussing it, in game, with the FC owner or ranks.