Astral Ring Melds

[PArcher]

I would meld:
2 VIT 3s (much cheaper than a VIT4, but if you have the gil and want that extra point of VIT get a VIT4 and VIT1 instead)
2 SA3s (Crit)
1 QT3 (spell speed) or HE2 (Acc)

EDIT: my Astral Ring is for a healer, with 2 SA3s, 2 QT3s and a VIT3 (I'm also really poor), so going VIT4, 2 SA3s and 2 QT3s also isn't a bad choice if you have the gil (also factor in the fact you're likely to lose many materia melding those 4th and 5th slots; SA3 run 25K-30K on my server, QT3s around 20K...trying to finish melding my Rose Gold Earrings and wasting so much trying to get that last meld)