I spotted a neat little item as I was reading the Book of Ebon Tides...a Spidersilk Rope (p.211). It doesn't say its a common item, just that it's magical, 50feet long with loops to aid climbing, has a sticky end instead of a grappling hook, weighs ounces and will fit in a pocket.
What do you think @bwatford Would this be allowed and if so, at what cost?