So I just came up with a way to figure out how much your gear is worth. I'd like to call it "greater essence equivalents". Here's how it works. For each armor you have like 4 stats, but you want to know if that piece is good or if you can replace it with essence gear and use those essence types for it. Or you want to know if the new armor/jewel drop is good or not. Here's how you can tell:
1) Write down all the stats from that armor drop
2) Divide each stat by the greater essence stat version for that level (https://www.lotro.com/forums/showthread.php?550304-Socketed-Armour-and-Essences)
3) Add up all the numbers you calculated
4) Resulting number is "greater essence equivalents" or how many greater essences you need to make that armor piece
Here's some examples comparing the Osgiliath t2 armor box drops:
helm
0.926 (from 126 might)
2.647 (from 360 vitality)
0.523 (from 1286.4 inc healing)
0.523 (from 643 parry rating)
4.619 - greater essence equivalents
boots
0.662 (from 90 might)
2.647 (from 360 vitality)
0.662 (from 90 fate)
0.654 (from 1810 tac mit)
4.625
chest
0.926 (from 126 might)
2.382 (from 324 vitality)
0.654 (from 804 parry)
0.654 (from 2450 finesse)
4.615
gloves
1.059 (from 144 might)
2.382 (from 324 vitality)
0.523 (from 1286.4 inc healing)
0.523 (from 643 evade)
4.487
boots
0.662 (from 90 might)
2.647 (from 360 vitality)
0.662 (from 1810 tac mit)
0.654 (from 2020 crit def)
4.617
boots
0.662 (from 90 might)
2.647 (from 360 vitality)
0.654 (from 1810 tac mit)
0.654 (from 2020 crit def)
4.617
So looking at these, ignoring armor and set bonuses, switching to 5-piece essences would be an upgrade, but replacing the gloves would be the largest upgrade. But what about the 4-piece essence armor? Well, that's easy since the equivalent of one essence slot is one essence slot:
4-piece essence armor:
4 x 1 essence worth
0.875 (from 119 main stat)
4.875 greater essence equivalents
So, any of the 4 essence slots is more bang for your buck only if you ignore set bonuses (which you do if they're trash), but the 5 essence slots are the most valuable. Assuming you still have your goal stats in mind, like a certain amount of main stat, vitality, mastery, etc, this can help figure out how to best reach those goals. Obviously if you do not want a fate armor piece on your tanking build, you'd avoid those pieces, but you can see which ones are equivalent.
P.S. I'm lazy and I don't plan on doing this for every gear in the game. Could someone make an excel sheet with the value of all loot in the game?
(posted in lotro forums at https://www.lotro.com/forums/showthread.php?569265-GUIDE-How-much-is-your-gear-worth-Greater-Essence-Equivalents&p=7374625#post7374625 in case someone posts an excel sheet there)