I think it will go up over time. Here is my reasoning.
- currently, GP is only necessary for things like rares or possibly buying certain skills. However most people, unless they are merchers, had no need for huge amounts of gp or rares.
- with the reintroduction of free trade, people who were previously reluctant to buy gp because of all the difficulties (needing certain requirements, an xfer method, handing over your account to a gold seller, and need to not play your account for a while), will be more than willing to purchase gold due to how easy it will be.
-Staking alone should cause a huge influx in GP buyers. staking is an addictive hobby, and very few people are good at staking. As such, they will buy more so they can fuel their staking habits, since it is an enjoyable hobby.
As such, these are a few of the reasons why I believe gold will rise within a month or two of the release of free trade and staking.