Terrible experience purchasing through this service. Since the book came out a few weeks after the CD, I emailed customer service to ask if there was any way to combine the items. They confirmed that I could in fact combine my orders to pay 1 shipping, rather than 2 separate charges. I asked to make sure I wouldn't be charged twice and they confirmed. So I bought the book, asked to combine the orders, and they confirmed they would combine them.
Then, they went ahead and shipped them separately anyway. I asked why they did this, after confirming with me, and they told me it was never an option to combine "pop-up shop" items. When I told them they told me I could prior to my purchase, they basically shrugged and said oh well.
This wouldn't have been an issue if they just told me from the start that I should cancel the first order and re-order them together. I believe they purposely misinformed me so they could charge me twice, rather than once.
TLDR: Customer service will misinform you so they can charge you more in shipping.