I think it's okay as long as people that have already purchased the books can download them again without having to repay. I personally hate it when they do like an Anniversary Edition of some book I love or whatever, and the publisher goes through and adds a bunch of crap, then charges $15 like it's brand new.
Right now I'm working on my serialization idea and I'm going to put out a collection, then later have a Perfect Collection where all of one story is put together in a single ebook for a single price. Hopefully if the first volume does well, I'll be seeking other authors for any others
