Yes, it is definitely possible.
Recently, I had purchased a book from Google Play Books.
I then exported it as .epub file and requested for a refund from Google Play stating the reason that I don't need it now. After some time ( say few minutes), I got my refund back. Also, I still have the epub file downloaded in my pc.
In paper books editions have new edits and other editions so they are a new published book.
The same thing is true with eBooks and new edition will require you to buy a new copy of that edition.
However with an eBook the publishers can updated the ebook and some do to fix typos and other errors. Then you just need to redownload them.
I am sure that there ...