As many have said, the biggest benefit is it will stop third party gold sellers setting up camp.
Bare in mind the WoW token system is an example of supply and demand along with market forces. The price on classic will be significantly lower than it is on live due to the difficulty of making money. 1000gold back in vanilla is probably equivelent to about 400-500k now so guessing that on EU servers classic token would be between 700-800g