I was about to ask for a "Save for Later" feature in the Logos shopping cart (like what Amazon.com has), but I figured out a work-around for the reason I wanted it.
I tend to go on Logos "shopping binges" every so often, where I'll add everything I'd love to buy into my shopping cart. But then I let it sit around there for a couple of weeks or more until the impulse to purchase wears off. I'll remove many of the items from my cart and then finally check out.
However this evening I found a need to immediately buy one book, and I didn't want to delete all the other items I'd painstakingly collected into my cart just in order to check out with this one book. I wished for a feature like in Amazon.com where you can click a button next to items in your cart for "Save for Later" -- which will keep them in your cart but move them to a separate section so they don't get purchased when you check out.
But, as necessity is the mother of invention, I figured out another way to do what I wanted: open up a different browser and do the single-book purchase in that one. Each browser has its own set of cookies and thus its own mutually independent Logos shopping cart. So I went into Firefox and put that single book in my otherwise empty cart. It didn't affect the cart I've got going in Internet Explorer at all.
Very pleased with myself! 
