title_body: How to choose where/which to buy ebook/book online? When searching for George Orwell's 1984, different results appear where one can buy the book. Like on kindle, or at play store here and here.
  
  Can someone help me understand as to
  
  
  why all the options have ISBN numbers?
  why there is difference in the page count?
  the ones in play store seems to be from different publishers. Do the different publishers also have some extra contents added?
  to what extend does the publishers have liberty with the book, well apart from the cover design?
  how do I go about and choose which one should I get?
  Am I missing something obvious that one should know for purchasing ebook?
upvoted_answer: Methods for estimating page count for ebooks  depend on a variety of things and don't really indicate anything.  
  
  Different ebook distributors use different ISBNs. It used to be that print publishers would have a single ISBN. Nowadays, when you publish on a distributor's platform they will tend to assign an ISBN specific to the store. 
  
  Google Play stores tend to have the same store for everybody, but Amazon has stores for each region or country. I would expect that Google Play Books to have more editions  -- especially for public domain titles. 
  
  With print editions, there are often different editions with different covers and prefaces and annotations. That is especially true with books for classrooms. Typically less developed countries may produce cheaper print editions and be priced accordingly.  With ebooks, there are not as many different editions unless the work is public domain. It can sometimes be different to tell the difference among them. 
  
  You may not realize this, but 1984 is in the public domain in certain countries (but not the USA). 
  
  If you are unsure, the best thing to do is to check the main website for the author and see what editions that the author's site links to. 
  
  Finally about Orwell's 1984 and Amazon, I see that various Kindle editions cost from $2  to $2.99 (for a collected novels). Also, translations have different prices. If you live in a country where the novel is in the public domain, you may see more editions (and a greater variety of prices).