I recently changed my profession to mining. Much more profitable than skinning in my humble opinion.
Well anyways I was surfing the AH for some silver ore because I am lazy and didn't want to level it by hunting for ore. And I noticed that silver bars cost alot but silver ore is worth much more.
On my realm, which is Terenas, silver ore is quite rare to come across in AH so I decided to go farm some and I am selling it for around 20g for 5 pieces. I would suggest checking your AH to see how much ore is going for. Quite a profit.