On my server netherweave cloth averages 3 to 3.5g a stack on the AH. I notice a lot of people undercut to around 2.5 gold. I thought about buying and re-listing the cloth but as you know the AH gets a cut from the seller.
Here is what I came up with and so far I have made about 40 hold in the last hour.
I buy all the stacks of cloth that are selling for 2.5g a stack.
2 stacks = 5g
I make a stack of heavy netherweave bandages which vendor for 6g.
Thats 1 gold profit right there for making bandages with other peoples cloth.
As an added bonus now tonight the lowest price per stack for netherweave cloth is 3.5g currently.
The cloth I farm I AH for 4g a stack and I buy up everything below 3g to keep the average price above vendor value. Win either way.