Yay! I'm so glad someone else is feeling the love for this particular title. It is one of my favourites. :)
As for the page count, I would go with the officially listed page count for your version. If there is no page count, I would check the print edition on Ammy.
My version is the same as the ebook listed on Kobo, which as I mentioned is listed as 224 on both Kobo and Amazon, so I guess that's official? A lot of ebooks aren't that consistent though, so I've been referencing what look to be suitable print versions on occasion.
My liking for the Poirot books has been a bit up and down, but this one wasn't nearly as loopy as Death in the Clouds, although events (and murders) do seem to run away on the killer.
I looked my print edition up and it's 319 pages (it's the first printing of this specific edition and they are smaller in size). So it is safe to say you can net the money for the 200-400 page range :).
As for the page count, I would go with the officially listed page count for your version. If there is no page count, I would check the print edition on Ammy.
My liking for the Poirot books has been a bit up and down, but this one wasn't nearly as loopy as Death in the Clouds, although events (and murders) do seem to run away on the killer.