THE WEAPONS MARKET ...
It is a very good idea to create a WORLD WEAPONS MARKET. Not only tanks, but also artillery, aviation, warships, all equipment and missiles. This would be REAL LIFE in the modern world.
But the maximum selling price should be any, not limited by anything. That's just the lower limit of the sale should be limited by the cost of the weapon produced and not lower.
But you can't trade in infantry.
It would also encourage players to buy more gold.
This would be worth considering for developers in the future.
However, thanks to the developers.
They are working hard right now to modernize this good game that has a good future.