The first thing that surprised me about this classic tale, is it’s brevity. I hadn’t realised it is, in essence, a short story. Because of this it’s almost always published with other appended stuff. And often quite a bit if the latter.
This Penguin English Library edition adds The Bottle Imp, also by RLS, and a short essay not by the author, (?). But it was the slimmest/cheapest version I could find at the Ely branch of Topping Books.
It could easily be read in one day. If all or most of that day was given over to it. As it was, with work and other life stuff intervening – inc. a lot of sleeping in my case – it took me two days.