Lets make more items worth around 2-4mill, and we can call this game 3millscape
what.
If by that you mean the update where all bosses were made into group bosses, then it's because so that a lot more items would be accessible to lower levels.
Another thing to consider would be to always have the most powerful items for every combat style be something that has charges, can't be repaired for coins and disappears when charges run out, otherwise we'll just continue to run into the situation where every pvmer has the top tier equipment and has no need for any more money or items.
Could be done to Nex armour and make them a bit more common as a drop + add more charges in return I suppose. Once equipped the item becomes untradeable. If dyed and the item reaches 0% charges you'd get the dye back.
For weapons that concept is pretty bad imho as you still wanna use those weapons to get the armour that degreade into nothing. Repairing with gp works fine for them.
Edit. Also why it works for armour is because you'd probably ask yourself "Do I want to use this/waste charges to complete a slayer task?" You'd probably want to stick with lower level armour on regular slayer and use the better degrade-into-nothing armour at bosses only.
The main problem with the economy at the moment is the crisis of basic things and low level gear, not the end game equipment, so you completely missed the point. And there is not enough nex gear as it is at the moment.
However, there are too many demon weapons in game, especially the melee ones, which could be solved by a simple drop rate nerf.
another pointWhile i do agree that the group bossing update was good for the community overall, i'm not so sure about its influence to the economy, because if any one of the players now needs an item, they can just go pvm it themselves instead of buying it. Which leaves the economy at a point where it's impossible to sell anything.
There is too much supply and too little demand at the moment.
EDIT: Mind the language in your title next time and people might take you a little more seriously.
EDIT #2:
Skilling suppliesAdd a boss something along the lines of raids and such, so that the skills that are mostly useless would have some uses in the end game stages.
Perhaps where you enter a raid without any supplies or armor with a team and have to gather everything yourselves in order to kill the final boss. That could be interesting.