Just a heads up that I stumbled upon this while gearing my alts. Although all the renown purchasable gear items appear correctly in the upgrade finder lists (using either the purchase or renown filter options), the upper level items all show up as item level 376 vice the 389 item level they actually are (which of course skews the upgrade calculator incorrectly). This is happening for all categories of this equipment (cloth, leather, mail, plate, legs, shoulders, helms, and chests).
After doing a little research, I found that although the Wowhead item number links are correct in all cases, the Wowhead links themselves all have incorrect information. All these items are listed as a base 376 (which as far as I can tell has never existed in game), and one must go to “item version” in the link and select “World Quest 2” to get the 389 item level. This adds the “bonus 1485” syntax to the item link.
Here are the pertinent Wowhead item numbers (in case that would be helpful):
Dragonscale Expedition Legs
C-198738
L-198739
M-198740
P-198741
Maruuk Centaur Chest
C-200467
L-200466
M-200465
P-200464
Iskaara Tuskarr Shoulder
C-199890
L-199888
M-199891
P-199889
Valdrakken Accord Helm
C-199763
L-199765
M-199764
P-199766
This certainly isn’t a pressing problem (and I don’t know how hard the fix is given the incorrect information on Wowhead), but I wanted to at least pass on the information I was able to find.
Thanks as always for the outstanding site and tools!