Gold just stacks and stacks and stacks and stacks. In the current system the most powerful player would have no use for (as he can get anything quickly by hunting) and therefore would rather use his items for geosids. Therefore rarer items would never get sold at the merchant, therefore nobody would ever buy items except in rare cases that are not a general rule, and in those cases the prices would be extremely high.
Gold has to be spent to have value. Some ideas of how to give gold value.
Make common consumables unavailable from geosids and make them purchasable and drop only. (provide a merchant that sells them)
Have merchants out in the wilderness that you have to defeat difficult monsters to get to. These would sell rarer items or rarer consumables.
Set common consumable prices kind of expensive. In hour of hunting a level 15 fighter should gather enough gold to buy aprx 5-10 trans wands. This gives higher level players who are finding an abundance of wands an opening to undercut the merchants and sell cheap and still make a profit.
Allow Guilds to sell permission to use their Geo's. They could sell amulets that protect from the guardian and allow a one time or five minute use of the Geo.
Make very rare purchasable guild benefits/items so that guilds have a reason to horde money.
Make an exchange rate for geocite so that people can drop gold for Geo items.
*Editted for a new idea and to make my opening economic theory make more sense*