Stats wise weapon quality matters the most anyway, the difference from epic to legendary armor isn't spectacular and from epic to legendary jewels is almost negligible. My characters have both weapons and armor upgraded to legendary because I have hundreds of tempers and my bank account grows pretty fast even without selling those. I only use legendary jewels if they are part of a trial set because I do them on veteran pretty regularly, but I don't bother to buy dungeon set jewels in legendary when they come in gold at the Cyrodiil vendor since the price doesn't justify the benefit. The only exception I've made was during the Midyear Mayhem event when I've spent about 6M AP on legendary PvP set jewelry I didn't have already and 2.5M on the Militant Ordinator style pages a bit later, simply because I didn't have much else to buy with them.

Doing daily crafting writs on 10 characters, and that alone amounts to about 25K in net profit per day, considering the price of materials but not considering the tempers, master writs (~50 vouchers per day on average, most of those in low value but cheap & fast to craft alchemy and enchanting ones) and multiple surveys I can collect later and refine which amount to much more in the long run. Leveling a character to 50 and transferring trash items trough the bank for them to pick apart raises crafting skills to 50 within a week or so - only enchanting must be started earlier but alchemy and provisioning can be done in about 30 minutes each if you have the ingredients. Cycling through those only takes around ~40 minutes per day with loading screens considered, and I picked a location that allows me to cycle pretty fast between the crafting stations, bank and turn in point.