For those projects that are special, I like superwashed wool...you can stick it in the washer and dryer. I have gotten spoiled. I do buy some yarn just like you said for certain projects, especially when I'm designing something big, or want it to be super washable, but I surely like working in high quality natural fibers. I used to think people who said that were yarn snobs...but I learned they feel different in the hand....
I'll have to look for that for the next project. I have about 30 years worth of magazines and books - every one has at least one thing I want to make! Have you tried any of the soy silk yarns? I've even read about a yarn that is infused with Teflon, so can't be ruined by spilling anything on it.
I admit to being a yarn snob! I love the nice stuff. But I get a lot on ebay. Really good prices.
Though I love my LYS and do support them. Sometimes too much. *g*
I wish I could post a picture of my stash . . .