I've been to bali twice, but did not see batiks being made. I loved it there, and would happily go back again. Everybody is so friendly and everything is very cheap (I do remember buying some super cheap fabric), although keep in mind this is considering the prices in Australia and the cheap airfares since Bali is a lot closer to Australia than the U.S! I think it is a great idea, depending on what kind of a resort you stayed in. Although it might just be me who prioritises lounging around the pool at the resort :D