Perhaps I am misinformed and using a different addon than what is recommended, however AtlasLoot is very useful when shopping for Crafting Reagents, referring to AtlasLoot's recipes. I use a secondary addon that previews the vendor and latest auction scan price within the tooltip. When I press shift, usually the quantity represented will multiply that price, and it shows me the overall product price. (I believe the addon is called "Pawn") Currently, pressing shift while mousing over doesn't manipulate this price preview, and remains to only show a single unit's price.

The UX quality within AtlasLoot would greatly benefit, if we were able to have this tooltip compatibility. Maybe I'm barking up the wrong tree, and it is up to the other addons to provide this compatibility. I figured I would at least provide this feedback.

an example of a multiple units, priced

AtlasLoot's mouseover tooltip

This is not a complaint, merely something potentially constructive. Have an awesome day!