I kept my LW'ing up at a high level the entire time I levelled my hunter. I make plenty of money from the process. I did most of my levelling through grinding and skinning beasts. Here is what I do:
Take a few quests and grind everything you can on the way. Try to grind beasts so that you can skin them all (I avoid and hate spiders). I have never bought leather from the AH. I skinned it all. Only do things in the game that will advance your leatherworking or your character level.
Because most of your character levelling will come from grinding, you will get some nice drops that will be useless to you. Sell it all. Get bigger bags. Save everything you can and sell it all. I get some purple items from drops and I sell them immediately. Occasionally, I will get a drop that will suite my character well for his level. I wear those. Everything else I wear is made by me. I look at the AH and there isn't much out there that is better than I can make. It is trivial. Just keep your leatherworking skill as high as possible and you will be able to make things that will suite your level.
I did by a few top of the line weapons from all of the vendor crap I sell.
Also, people say that your LW'ing items will not make you money at the AH. That's strange because I make several gold every day from this. I make items to level my leatherworking skill. It may cost me to level my skill but it costs nothing to sell it. If I use 14 heavy leather, 2 heavy silken thread, and 3 wilvine, that I found grinding trolls to level, then I sell the item for 2.5 gold at the AH, I make 2.5 gold minus the cost of the thread plus, I levelled up my LW'ing at the same time. To me, that is pure profit.
Now, I have 300 skinning and 280 LW'ing. I kill and skin beasts 2 levels higher than me and I cannot spend the gold I make. It is gauranteed that I will have epic mount money by the time I am 60. I sell my vendor trash every hour or so and that gives me several gold. I go to the AH and there isn't anything decent for me to spend my money on. So, I just keep on trucking.
The key points are:
You do not need the super duper 100+ gold items at the AH. Way over rated. Just upgrade your weapons if you don't find them in the process of grinding.
Sell everything you find. Bear Gall Bladders are actually worth a lot of money.
Everything you do must be centered around upping your LW'ing skill. If you cannot get to the next LW'ing skill level without levelling your character, go quest and (most importantly) grind skinnable beasts, fill your packs with leather in order to level your character. As soon as you level go back to leveling your LW'ing.
I gained 3 levels just grinding turtles for their scales. I also gained several levels grinding Scorpids for their scales. Then, I levelled by grinding elite dragonkin for their scales and I found a couple of purples that brought me over 300 gold just for those.
Anyone who says that LW'ing won't get you the money you need or the gear you need to play the game effectively is wrong because I am doing it entirely solo without struggle at all.