It is the 'getting bookshops to stock it factor' that's the bugger. Each shop usually has its own buyer, so if you self publish you have to go around all the shops yourself and convince each one to stock it, even to chains like Waterstones etc.

As you say, genuine self-publication is fine - it's the vanity variety that's kak. I do know a printer that will do short runs of books similar to the Shire series, but short runs ain't cheap. You're lucky to make a small profit.