I've personally done Ores, Ingots (half value of Ores), Shiny Drops (Redstone, etc, based on Pulv'd Quantity of raw ore), Saplings (excluding forestry saplings), Wood Blocks, unprocessed farm products. Ignored ingots that have special crafting requirements and materials that are unique (thaumcraft 3 crystals). I've also used my own values calculated on world gen rarity and usage (Cobble is 2, a diamond is 79k) plus a 10% loss rate in the conversion, along with custom block recipes.
Still can be "abused", but not as much as EE2 days. We have an amusing self feeding chicken farm to generate mob essence. Feathers and Raw Chicken are turned back into eggs, to chickens, adults ground up. Self feeding loop.
Creating EV though for every single item is insane though, and does defeat the crafting aspect of the game.