OK, I had a long message for this but it got erased and I am not doing it again. lol.
I started at lvl 26 with advanced support to lvl 31. Then i did the rest to lvl 35 without support - 9 lvls.
I bought 17 stacks of wool off the AH for about 12K each and made 8 stacks of thread in the end. Thread is currently selling for 40K a stack so even though I spent about 220K I have 320K worth of product.
Don't waste your time trying to farm this like I did for 4 hours...just buy it, skill up and move on to bird fletchings. Sell your thread for profit or save for other crafts :)
Enjoy!