The RAF XP bonus makes a big difference. I think my shamans must have been unable to pay for spells as early as level 8.

The best solution is to level every gathering profession. Yes, it does take time, yes you have to stay in the same zone longer just to farm, yes it hurts you /played time but I think the reusult is well worth it.

I would suggest having both herbalism and mining on the same character, that makes the tracking easier.

By the way, to me enchanting is also a gathering profession. I made an enchanter, let him loot every BOP item, gave him every green item, he disenchanted everything (stock items for a while, DE'ing objects provides some enchantement skill-ups at first), and levelled from the obtained material. Selling the greens seems like an quicker mean of making money, but at higher level, being able to desenchant in instances is priceless.