Why should you invest gold in flying faster? Well, for one thing, if you are questing in an area, you’ll be able to finish those quests faster, when you can get around faster, and that means making more gold in less time. So look at this as an investment. But 310% flying costs 5K, so consider it a big investment. So how would you like to get a discount?
Would it help, if you only had to pay 4K instead of 5K?
Reputation is your friend, once again, to getting better prices in WoW.
If you have a horde char, you should purchase your fast riding abilities from Wind Rider Samamba in Warsong Hold, Borean Thundra, or from Maigra Keenfeather in Valiance Keep, Borean Thundra.
You need reputation with Warsong Offensive (horde) or Valiance Expedition (alliance). The better your reputation is, the lower your price will be. Exalted will give you the best price, 4K.
If you want more info, you can read about riding in WoW here.