Skinning is completely worth it, but it isn't the only thing at that level worth keeping for cash!
At lvl 7, I've always killed boars in durotar for the meat. For the character I've taken up cooking in, I kept everything to lvl up. For my alts(mostly for pvp) I always kept the meat and sold it at 1G a stack. A great way to get a cashflow going, especially when you're skinning them too!
On an aside, I also had a question. Is anyone able to sell hides at a decent profit(I have skin/herb on my char)? I've just been throwing them out and cursing whenever I get one. It sells for nothing, and isn't worth the slot to keep.
Anyone else agree?