It has become quite difficult to find rank IV and V recipes since One Tamriel. This is due to the generalization of level-scaling, and the fact that once a character has reached CP150, none of the alts can experience the Level 50 to CP140 content. There are very few zones where it is still possible to find such recipes - Coldharbour is one of them, but now that there are so many blueprints, the recipes themselves got diluted into an ocean of random drops.

This increased rarity accounts for the very high prices of rank IV and V purple recipes - usually between 15k and 50k. There was still a consistant way of finding them (and earning gold by selling them), which consisted in willfully keeping all but one character at rank IV or V of recipe mastery, in order to obtain them, for example, by doing daily writs. But now, keeping unmaxed alts means sacrificing a chance at sealed writs. Many players will thus max out the recipe rank of all their alts to get the valuable golden drops. This will probably result in a drop in offer. Simultaneously, the demand will rise as people will need the recipes they miss to successfully complete the master writs.

This makes me fear that the rank IV and V purple recipes will become virtually nonexistent in the game.