Supply and demand

when there is not enough supply and too much demand, price tend to rise
when its the opposite the prices tend to go down

a market always regulate itself and thats why the gold prices are going up

This

A lot of poker players are buying osrs since it's an easy way to convert to $$$ since you can't sell fg. There's more people trying to cash out than there is people on jsp farming gold to sell.

This isn't a controlled market. the gold selling sites are.