Why is the Vial so rare? Because getting it requires that players max out not only their Alchemy, but then also Archaeology, since the formula to produce the vial is only found in Tol'Vir digsites which: 1) Do not appear at all until 450 skill, and 2) Even once you're at 450 skill, they're at best a 15% chance of appearing.
Even then, the formula itself is not assembled directly, but is a rare drop from the also not terribly common Canopic Jar artifact.
So, in short, the Vial pattern is rare because it requires two maxed professions, and an incredibly long grind to locate.
That said, even if someone on your server has the pattern, the odds of it showing up on the Auction House will still be somewhat low because as Raven Dreamer points out, the materials required to create one are incredibly expensive, and largely bought from a Vendor. Thus, even for those with the pattern, they may not be interested in or capable of expending the capital required to produce one just to have it listed on the AH, preferring instead to produce only on commission.
My suggestion? Get the materials together yourself, and then look for someone willing to craft it for a commission, either through your realms forums, or simply in trade chat.
Set your hearthstone to to Dalaran. Be in Northrend saturday 14:00. Fish until you catch a Blacktip Shark, then hearthstone to Dalaran to turn it in.
Btw, I choose Boots of the Bay as reward :)
Best Answer
The auction message delays were introduced in patch 2.2.0. There doesn't seem to be a definitive answer about why Blizzard introduced it, but this thread discusses reasons as to why. Some include:
A lot of the people on that thread also remember seeing on the official patch notes a reason as to why the delay was introduced, and it was to get gold sellers of the market. Unfortunately, it looks like the official patch notes are no longer available off the games website.