Jason

Nilphas, in The Merchants Inn, has 2,500 gold, upgradeable to 3,000. Aurelinwae is great in the early game, but once you max mercantile, you'll be selling your stuff to Nilphas, then heading over to the Mystic Emporium for soul gems and recharge.

Emerald weapon was doable with all your materia as long as you have Final Attack equipped with Phoenix. I had Knights of the Round by that point and I just basically spammed that. When that crazy attack finally hit me and killed my whole team, they were all brought back with full life by Phoenix.