I had a go at writing a book once. It was fictional but based on actual happenings on Valiant tankers in the early sixties. I wrote it during my ample free time in China and the Solomon Islands. On completion it stretched to over 200 pages of A4, say 400 in a book. One or two people I showed it too were enthusiastic, others not so.
After months correcting the grammar I investigated self publishing. It was not going to be cheap. There was not going to be a lot of change out of a £1,000 to get it published in basic form and should you want to promote it you were looking at another £1,000.
The returns by the author are pathetic. It's the publishers and the bookshops who coin the money. A book selling at £17 would only realise 50-75p a throw so you are talking about 3-4,000 before breaking even. I didn't have that many friends so I packed up that idea.
There are a few people that have tried. They have cupboards full of them.
Anybody wants to download a copy, give me a shout.