The Onyxian Drake is my favourite looking drake based mount in the game (including the protos). I was a little reluctant to pay too much for it, and was surprised that I managed to grab it for a little over a quarter of a million gold.
The Black Market Auction House is getting me into a lot of trouble, and it is a little scary that in the recent past I've spent more than the gold cap on mounts.
Regardless of their individual aesthetic appeal, mounts have a number of factors that change their value.
- Sentimental association. Even though Mimi's Head is one of the best looking mounts in the game (in my opinion), the mount is really all about Ulduar. I can't mount up without being flooded with fond memories of one of my favourite raids. It is more than just riding in a robot head helicopter, it evokes the first tram ride to that robot and the gut wrenching process of learning to defeat Yogg Saron (and educating people about the fight over and over and over even through new expansions).
- Ease of farming. Contrasting the last two mounts I purchased... Mimi's Head requires a raid team, even if it's just a small one... and killing most bosses in Ulduar, which is a BIG raid. The time and organisation investment is sizable, even though Yogg+0 itself is getting exponentially easier to beat as expansions come and go. The Onyxian drake drops from both 10 and 25 man and does not require a hard mode. 10 man is soloable, and at worst, if you can get a couple of friends together it is very quickly farmed each and every week (similar to Tempest Keep for Ashes of Al'ar).
- Drop Rate. Unless Blizzard comes right out and tells you what the drop chance is for a particular mount, you're really just guessing. The best guess is usually derived from Wowhead, who have a reasonable sample size to work from. It is worth getting even a rough idea of the ballpark drop rate before you decide to invest the time in farming (or the gold when bidding gold on the BMAH).
- Number of sources. The BMAH has introduced a great new source for mounts, and with enough gold, a much better chance of obtaining them when they eventually appear. However, many mounts already have more than one source. The prime example here is mounts obtainable from dungeons, where tanks and healers can get lucky with their [Misty Satchel of Exotic Goods]. My highlight from the satchel was the [Deathcharger's Reins], as well as many rare pets including a [Tiny Emerald Whelpling].
- Rarity. The factors above, other factors (such as server raid progression and even duping) as well as the newly introduced BHAH conspire to create a certain number of rare mounts on a server. If I saw Onyxian Drakes crisscrossing the skies in Pandaria, would I have paid over 250k for it? Probably not, and time will tell just how quickly the BMAH dilutes the value of these rare mounts as the expansion progresses.
While we can rank the ease obtaining a mount and its scarcity objectively, how much anyone is willing to pay is very subjective. I've heard of mounts like Mimi's Head and Ashes of Al'ar going gold cap very quickly after being posted, so the competition from realm to realm will vary enormously. It is a good idea to start thinking about what different mounts are worth to you, and start saving! When a mount appears, I recommending looking at your current gold situation and deciding on a limit right away. When it comes to bidding, the later the better, and I might post on the science of narrowing down an auction end time later on.
All in all I am very happy with my recent acquisitions and have managed to stay above the gold cap so far. I'm really looking forward to posting my graph of liquid gold since I finally started tracking it before Mists of Pandaria was released. The BMAH has introduced some significant bumps in the short time it has been active.