On my main I had saved almost allthe cloth, especially all the netherweave cloth. After my main reached 70, I could train tailoring on my priest alt from 1 to 374 without spending more than 100g (new patters from trainer, limited patterns, threads, and just a few stacks of netherweave).
Depends on how much time you think you have left until reaching 70, and how patient are you.
The last point has eluded me, I made several Imbued N. Robes that didnt give any skill up. Oh well, one of these days I´m gonna get that point. /shudder