JustAbitCrazy

I only like to piece with all cotton thread. I just bought some Guttermann cotton thread at half price at JoAnn's (the thread sale ends today, buy three, get three free), but even at half off I think it's expensive: $2.50 for a 274 yard spool. The other cotton threads they had were 30 weight, which I consider too thick for piecing. I think what I bought is 40 or 50 weight because it is visibly thinner than those, but the spools are unmarked.
So, what's your favorite all cotton piecing thread? (I was looking at Connecting Threads...maybe for future reference?)