Ok here's an idea I came up with recently.

Let's say I really want to buy an elite marlin sword, I have 1.2 Mill to spend but currently prices are around 1.4-1.6 (examples)
A feature where I could place a BUYING ITEM LISTING
I actually put 1.2 million gold into this "listing" which is held there, and anyone can come along, browse these adds and exchange their elite marlin sword for the 1.2 million gold, I can then collect the marlin sword from CS whenever I please.

So the feature works like a backwards way of how it does now, but saves people from wasting time running around balefort shouting "BUYING ELITE MARLIN SWORD 1.2MILL" for 4 hours when nobody is selling and there may not even be any in CS... instead they could be spending time and money on elixers

Feedback from a dev would be fantastic, feel free to post in support/disagreement