Grepolympia uses quite a bit of gold and unlike most of the game (in my opinion) which is pretty balanced. In the normal portion of the game you can attack equally and have a pretty even chance of damaging an opponent, in grepolympia, you need to give extra gold to participate as often which gives an edge to gold-using players. In addition to this, with the use of gold you also can buy extra slots which help you train, get skill points and do better in the competitions. It is still a very good concept from inno, but I think it could be a bit more fair for people if they toned down the use of gold. Also it seems Muskies are in the lead for this part of the game as well, though there is a chance some alliances will be focusing all their resources to this event.
i have spent a bit of gold on this already but i can honestly tell you my best distance is on my free spin and the gold is merely buy laurels for ingame use all my bought entries are less than my free but i use the laurels to buy things in a shop so i say the more you wanna buy in the shop is the more gold you'll spend