The latest hotfix has made Vile of the Sands able to be traded. Now currently making the mount will cost almost 60k going by the average sell price on wowhead for Truegold bars. Now that may sound like a astronomical price but unless you want this mount for yourself early on you can easily sell one of these for an enormous profit.
Now there are ways to limit your cost to make these. You can transmute your own Truegold bars although it would take 12 days to build up enough to make 1 mount. An alternative would be to find other alchemists willing to sell their cool downs. You are still however looking at a substantial investment to create one.
Still another alternative, while you may be one of the few with this recipe would be to make one to sell in trade chat to drive interest in the item. Once interest has been driven and more people want it you can offer to craft one for them if they are able to obtain the vendor parts and the truegold for you. You then craft the mount and charge a mark up for both the parts you provided and crafting it for them. This way you will not make as much gold per mount but I believe more people will be interested if you offer this alternative and in the long run you will make more total gold.
Giving up control of reagents will take away from your potential profit margin but at the same time it will keep the amount of gold you personally have to invest to a minimum.
On a side note if you were wondering. The vendor is not associated with a faction so the only way to decrease the cost on these items is through the Goblin racial and the Guild perk Bartering.