How often is too often to go to the yarn store?

I have completed the applied I-cord trim on the pug sweater and added the button loops along the back. I am still debating whether I should add some sort of sleeve at the legholes and if I want to give it a collar or different trim at the neckline.

While I am in deep thought on that project, I decided to cast on for the Koolhaas hat. This bugger is off to a rough start. In my first attempt, I messed up the foundation stitch pattern and had to start again. Then , I somehow doubled back on a dpn causing enormous confusion until I figured out what I had done. The third try seems to be going more smoothly, but I keep changing between my Needlemaster circulars which have an awful join and my bamboo dpns which have very dull points. I may break down and buy a set of Addi Turbos, but I think I've been to the yarn store enough this week already. Here is my progress so far.

I also wanted to share the other yarn I picked up last week during the anniversary sale at The Shabby Sheep. The brand on the label is "Andes" but I can't find anything about it online. I had originally intended to use this to make the second pug sweater, but I think it is destined to be a scarf instead.