Before the wonder cost increase to 6000 all resources, wonder race is popular.
I feel change cost is just a easy win, it did not solve the problem.
Let’s rethink about what the purpose of wonder, it is a building the expensive enough and can force your opponent come and attack. Problem is, why a wonder can be built by 1 player and win a 4V4 game?
So the solution I proposed, is make the wonder can be built by all the team player, but this may require many code changes. Then I got an idea, an easier approach, let’s make wonder still can be built by 1 player at cost 3000 for all resource, but make it built as “damaged” if is team game, and wonder timer only start when wonder got fully repaired, the repair cost is 9000 for all resources if is a 4V4 game. Because repair can be done by team player, so you can either finish it by your own, or call ally to help!
Hope we can see the wonder race again in the future!