"So for someone who's level 22 with 200 skinning, the answer to your question is you can wait until you're higher level before spending the money to get to the Master level (225-300). You probably wont be finding monsters that give you skill until you gain more levels anyway. And the types of leathers/hides you get out of monsters does NOT improve with more skill in Skinning, its dependent soley on the leve of the creature."
While I understand the point you were trying to make (i.e. 300 skinning won't get you thick leather off of sickly deer), if you don't have high enough skinning, you can't get some of the upper eschelon materials (from corpses left to rot by wasteful higher levels when possible).
If I'm level 15 and somehow successfully make it to 225 skinning (well, I'm 28 with 225 now anyhow), and I could also somehow survive the journey to a hunting ground with mobs that are being killed but not slain, and are significantly above my skinning level, then it is conceivable that I might want to have 300 skinning, in order to get those materials, however unlikely that whole scenario is.