Some Farming Notes

Embersilk cloth:

• Level 85 shadow priest, average iLevel of 330
• Potion of treasure finding @ 132g each
• Farming trogs in Deepholm for 1 hour
• 7 stacks of embersilk @ 47g/stack
• 5-6 tiny treasure chests
• 1 green item
• 43 grays, including a snazzy Pockmarked Hat

Results:

A net gain of 197g/hour. Counting the green item and the grays, and the extra gold from looting the trogs and the tiny treasure chests, let's be generous and call it 250g/hour.

Elementium ore:

• Level 85 arcane mage (like it really matters...)
• Farming in Uldum for 2 hours
• 21 stacks of elementium ore @ 70g/stack
• 2 stacks of pyrite ore @ 183g/stack
• 16 volatile earth @ 10g each
• 13 volatile water @ 10g each
• 27 volatile fire @ 15g each
• 7 green gems @ ~ 9g each
• 1 blue gem @ ~ 20g each

Results:

A net gain of 2614g, or 1307g/hour.

Conclusion:

Farm ore, buy cloth.

Then use your excess gold to buy up a Haunted Memento when someone lists it on the AH for a ridiculously low price.