Just wanted to add something that might help you, OP:
Recommended Farming maps:
Unit XP: Return to Ruins, Immortal Beast, Fiery Oasis
Gold: Deep Forest Road
Prince XP: Dragon Hunting, Immortal Beast, last Eastern Kingdom whose name escapes me atm.
Jack of All Trades: Remnant Vanquish 3, Base Scramble II

Listed earliest to latest, the later ones are better but obviously harder to access. If there's a good gold map besides DFR, someone else can talk about it. Personally, I found as long as you sell iron fodder and don't try to level Post CC40 plat/black units with bronze fodder gold generally isn't an issue until you start Awakening units, so I'd stick with either the unit XP maps or the Jack of all Trades.