Max Perception for Unspoiled Nodes

[Castillan]

There is zero point in melding beyond 340 Gathering total (which will hit the 90% gathering cap on unspoiled nodes, and 95% cap on clusters), 600GP total (since 650GP can't be reached practically and only offers minimal benefit to do so anyway), and for Perception, once you've passed the basic 320 value, just throw whatever trash perception material you have into any spare slots and don't worry about over-melding and burning tons of gil. My advice, aim for 335 Perception and stop worrying about it from there. Get 350 perception only if it's easily achievable with the material you have in stock, but don't go burning 1M gil to get it.

[NefGP]

90% isn't the cap anymore for gathering - I got 95% on clusters and 93% on everything else at 335 gathering.

No idea if perception/HQ caps changed.

[Raminax]

Clusters have always been 95%, though I'll admit that everything else at 50 was at 90%, at least the one-star materials. Can confirm I had 95% base chance with 347 gathering on Spruce Logs, Grade 4 Carbonized Matter and Prickly Pineapples at least.

This does mean that you can get away with 550 GP, using Field Mastery/Sharp Vision I in tandem with Blessed Harvest/King's Yield II for 100% success rate. Hail stuff!