Actually I thought of doing something similar: created a bunch of screenshots showing the stats of items in battlegrounds approximately 4 months before, started to input them in Excel table and even formulated some gearing strategy. However, reading that pvp will change in Legion made me cease the efforts.
A bit more constructive feedback:
*Lavishly Jeweled ring from Deadmines probably has inverted stats: at 20-29 bracket it should have 8 int 5 crit.
*Therazane exalted shoulder enchant is missing. It is like 20 g cheaper and provides slightly higher stats. Just checked, price the same, the difference begins at level 30.
*At cloak enchant section, some non-gift enchant versions could be shown
*At wrist enchant section, Superior Spellpower appears twice.
*At boots enchant section Tuskar's vitality(+4 sta +8% movement speed at level 29) could be mentioned
*Brilliant Spellthread increases spellpower and spirit.
*Enchant Weapon - Spellpower and Enchant Weapon - Healing Power should be shown in the same row
*Pyrium Shield Spike at level 29 should be 32-52 damage when you block with it.