I just checked wowhead and in my opinion, you get one good item that is BoP, boots. But then again, I am going to do BS as well, mostly for rune of warding and ward of shielding.

As for farming cloth, I wouldn't bother, you're time is better spent doing dailies and buying the stuff in my opinion. Assuming you are correct about 2kg to level tailoring, if you can get a full daily run in, you will have that in 2 days time.