Although you usually don't want to buy items to sell from vendor, some items can be sold for much more than you pay for them from the vendor. There are a few reasons people will buy a vendor item for a higher cost at the AH. They vendor may be hard to get to, the recipe only sells in limited stock, or the buyer simply may not know where the item is from.
I want to say that I purchased your guide this afternoon, and I am not even done reading through the first few sections of the Auctions guide. I took one of your tips today and went for it, and I made 8,000 gold in less than an hour, with almost NO work involved. I cant wait to see what else it has to offer, but I'm expecting I will be quite rich in not too long a time! Thanks!
If there would be a transmog server #1, all transmog vendors would transfer there and the market would get destroyed fairly quick. In general, Roleplay-Servers like Argent Dawn or The Aldor are better server for selling transmog. On high pop servers you have a lot of other players selling stuff and as a result, low prices. On low pop servers prices are acceptable, but you have no buyers. So there is not recommendation for a server really. Its up to you.
2. Once you have an interested buyer, stay firm in your price. This does not mean to never make them feel like they are getting a bargain. You can subtract 5% off the price and not be hurt as long as you still make a profit! Remember this, as that 5% may not be a big deal to you, but the buyer will feel special and might buy the item for the slightly reduced price. I can not emphasize enough that this is not the same as undercutting! Do not drop every good every time or you develop a reputation as a soft seller and people take more liberties in their dealings with you. If you give someone a constant 5% discount, then they begin to want 10% and then 15% until you no longer make a profit. Discounts are used when you feel that the seller may be pulling away and you really want to just profit and move on!