It has been a while since some of the official forum members mentioned about how to get discount on HEX.  I have never paid attention nor really tried but today I just gave a try and it does seem to work for a real, and though slightly cumbersome, they seem to be legitimate.

General idea is that HEX in game currency, platinum, is purchased through the Gameforge website.  One of the option that the Gameforge provide for payment is actually through the use of certain gift cards.  So if you can buy the gift card for discounted price and use it as a payment option, the end result is you essentially purchased the HEX platinum for discounted price.

Here is a exact step by step process.

  1. First log into your Gameforge account and proceed the platinum check out process, and select a payment method as gift card, which should take you to the link:https://pay.openbucks.com/payment_v3.php.
  2. Note the list of gift cards that are accepted as a payment method.
  3. Go to https://www.twosmiles.com/merchants to purchase a gift card.
    *Obviously, the gift card you are purchasing has to be on the list at step 2.  As of today, Sports authority is the one.
  4. When checking out the sports authority gift card, enter “SUMMER15” for the coupon code, which gives you the 15% discount.
  5. Now using the just purchased gift card, proceed and purchase the HEX platinum from the Gameforge.

The thanks goes to the official forum member, Zophie.

Source: http://forums.cryptozoic.com/showthread.php?t=37964&page=2