That is a great idea. We can do it with other achievements as well:
Invincibles Reins has been out for nearly 9 years. This should be sold in the stables for 50k.
Dragonwrath, Tarecgosa's Rest is more than 6 years old and should be sold for 100k.
Netherwing Drakes are at least 10 year old and should be purchasable in Shat for 50k.
Sometimes, taking what is "outdated" and selling it for gold can look stupid, especially to those who actually did it on their own after farming for it.