Why make it either/or? I publish both at the same time. Self publishers don't have the luxury that traditional published authors have - the costs for production met by the publisher.

When formatting and designing my books or my clients' books, I always start with the paperback, as that is the one which needs the layout prepared properly. Converting that to ebook is a relatively easy process.

When Trad books are released they charge huge amounts for their eBook knowing that is where the profit margins are. So they release Hardback and ebook at the same time, making very high returns, and then bring out the paperback at a price which undercuts indie authors. I can't price less than around £8 each for paperbacks so there's little wiggle room there. The solution for me is to release both together and aim for both halves of the market at the same time. Of course ebooks are increasing in popularity, but paperbacks are holding fast.