If you can't afford Melds, just stick with 4 + 4 + 2 Vit for the moment on all till you can afford Vit +8. That's what I did. That itself already puts it on par with Allagan Accessories. 247 Dex Tier comes naturally even if it is debunked if you equip full Gryphonskin, it is still an increase in Parry/Block Chance.

Best meld = Getting most stats for the least amount of gold.
Hence why rings melded at 8 Vit, 9 Parry, 9 Crit, 6 Det, 2 Vit is the best but good luck doing 3x Tier 4 Materia overmelds. Assuming my server which inflation is dire, Vit 8 is 200k Parry 9 is 90k Crit 9 is 100k, 6 Det is 95k, Vit 2 is 3k. Base case scenario you need 2.7 million gil to "reliably" meld them. Whilst going 4 + 4 +2 Vit would only cost me 50k gil.