I wrote my first post on Missives back at the absolute beginning of Shadowlands. I now have a lot more experience with this market and with prices stabilizing we can use a more sophisticated TSM approach.
Calculating the crafting cost
The big part of doing missives is to calculate the correct crafting cost. They all require different combinations of Umbral and Luminous inks, as well as a single Tranquil Ink. You crafting cost will depend heavily on how you source your inks, as well as which missives you craft.
The simple way is to just craft equal quantities of each variant, which ensures you use equal quantities of each pigment. This means you can stick to milling Death Blossom and Nightshade only. If you want unequal quantities of missives you will have to include other herbs, which makes the math quite challenging. At that point you are likely better off just valuing the inks at their market value and selling based on that.
The equal quantity cost
I did the math on the cost if you craft equal quantities in terms of death blossoms and Nightshade. If you do that each Missive will on average cost you 28.57 Death blossom and 2.86 Nightshade. This is great news as it makes the entire process of crafting and valuing your missives incredibly simple. You just buy 10 Death Blossom per 1 Nightshade, turn them all into inks and then missives.
At launch I used hard coded prices, but herb prices have more than stabilized and we can use dynamic pricing. If we value the inks at market value you will often end up posting your missives for too much, as the apparent profit is very low. If we value them at the base herb cost however, we will often be making a nice profit.
To do this in TSM we simply use the market value of the materials, by adding the itemID inside a paranthesis after a price source we can have an operation refer to the value of a specific item. So we will set the minimum, normal and maximum prices to multiples of the death blossom and Nightshade value. You can see the operation screenshotted below.
To maximize revenue you will want to repost often. The competition in this market is fierce, and items will sell or get undercut within minutes. Reset days lead to huge numbers of sales, and reposting often is important. I like to keep 2-3 stacks of each missive ready to go and just run post scans regularly. Then I don’t have to bother with cancel scans and triggering the AH throttle.
The TSM setup will post two of each using the dynamic pricing formula. It posts 1 at the time. The best way to use it is to just run post scans whenever you can when you are online to maximize the time your auctions are on top of the pile.