The problem here isn’t the astronomically low chances of obtaining a “recipe” item from the AtM chest (MK chest is misleading as it is the 2nd chance chest for recycled BLC unwanted items). Nor is it that the items are possible to obtain from it in the first place.
It is simply Greed and Impatience.
Those two factors along with the “stock market” central way of doing business of any sort in game (no peer-to-peer secured trading allowed) have all but destroyed the economy of the trans-server market. It’s the same reason that “regular” 400 skill exotics are, with few exceptions, all sold routinely for less than the value of their components, and why crafting is an “everyone has 9 mastered crafts and supplies their own items” rather than a “400 skill is an actual achievement (not by in-game award standards) and few people are willing to invest to attain it” system.
Accept that Arena Net gives literally no incentive to buy goods at a slight profit to the seller vs. crafting them yourself and find something else to pursue instead.
As for “everyone” having access to these expensive recipe items it is not due to their availability, let me demonstrate with the following formula:
51 * 10 * 4 * 60 = 122,400
This represents a very lowball figure of how many times the AtM chest is looted per hour across all servers – where 51 = number of NA/EU servers, 10 = (5×2) 1 full party in LA + 1 full party in LA overflow, 4 = number of runs per hour each party completes (15 mins vs. estimated at 5-10 by speedruns), 60 = number of minutes per hour / new group of 10 players per minute.
The dungeon opened at 12:00 pm PDT Sunday, it is now not quite 12:00 PDT Tuesday, so 48 hours. There were 42 confirmed Arachnophobia exotics at the time of the OP’s post (cheapest ~26g), and that number is down to 29 currently (cheapest ~45g), so we can assume the number of new postings is < 5 in order for the price to be driven up 19g, but let’s round it up to 6: 42+6= 48.
That’s 1 Arachnophobia being sold per hour. Let’s assume for every one being sold there is 1 looted and not being sold (a high estimate given that only those with level 80 THF/RNG can use it, and even amongst those I’d wager most looted bows are being sold). That means across 51 servers the most the chest could have yielded is 2 Arachnophobia exotics per hour, or 96 to date.
With a minimum of 122,400 attempts to loot it with only 2 being a success, the odds of getting one are 1 in 61,200, or 0.000016%.
The Crossing has very similar drop rate, while the Mad Moon (based on # sales since the beginning) seems to average about double (or desire to retain it is roughly half if the chance is the same, but let’s assume the worst).
So the chance to obtain any of these (not the one you want) is 1 in 15,300, or 0.000065%. Hardly a common drop, and those that get it are basically winning the lottery.
TLDR:
Problem is, they take a winning ticket down to the lottery office (BLT) and get the option: “Would you like 10 million dollars paid annually for 50 years at a rate of $200,000 per year, or would you like 1 lump sum of 3 million dollars right here on the spot?”
Greed + Impatience = “I’ll take my 3 mil now because it’s 15x as much as the 200k I would get now otherwise”.
And there, my unfortunate crafting friends, lies the problem.
they made the right choice – as this is a time-limited event anyway.