Warriors of Faeo, the fastest ones always win. This is not only true for the 500m dash but also for the  Diamond Race. But in this case everyone who takes part in the race actually wins! This is how it works:
 

We have set aside a 100,000  Diamonds. You can see total sum of  Diamonds currently left for sale in the center of your hunt screen as shown in the picture below. Every player on any of our servers who buys  Diamonds will get a 10% bonus on top of his payment! The total sum of  Diamonds he bought including the 10% is then be substracted from the whole amount that's up for buying.  

 

The 10% bonus is only available while there are still  Diamonds in the pot. So be quick about your business: After all, you are in a race with all the other player in the game!