Better Vendor Price
Shows per individual, current stack and full stack prices.
(that includes the sell price per unit)
Works anywhere including bags, vendors, item links in chat and the Auction House.
Also get Auction House DataBase (AHDB) to see auction pricing data.
Why is it useful?
Sometimes the regular vendor price isn't enough to decide what to keep and what to discard:
For instance imagine you have 4 something that sell for 12s and 2 of something else for for 8s and both are dropping right now
Well assuming they both stack in 5 max, you should get rid of the 4 as you can get 20s from that slot with the other item (vs 15s for the other)
But if one stacks in 20 and the other in 5 or 10, the calculation changes !
Unless you are a math wiz and can do all that in your head (and if you know the stacking size), you can use this addon to guide you!
(and if a math wiz, it'll tell you the stacking size too which you can't know otherwise)
How accurate is it / can I trust these vendor prices ?
It is using the official blizzard item API, not any custom database, so it's 100% accurate and always up to date!
More information
Works for both SL and All 3 WoW Classic (Era, TBC, SoM: where it's even more useful given lack of default vendor price)
Get the binary release using curse/twitch client or on wowinterface
The source of the addon resides on https://github.com/mooreatv/BetterVendorPrice
Releases detail/changes are on https://github.com/mooreatv/BetterVendorPrice/releases