I've seriously considered taking the 'one man' approach myself. I've found a number of ways to produce quality bound books at home that can rival those made by commercial printing presses. It can save me a fairly decent amount of money, plus I like the idea of having nearly total control of everything. I like the challenge of pulling this off as well.
The publishing company I make my living at (actually I own it) is a one-man show. It consists solely of me and my laptop. I do all the editing, all the layout, all the cover design, and all the paperwork for the state and the Feds. Right now I have around 120 print books available, and around 220 ebooks. Combined, they bring a pre-tax income of around $65k a year. (I should note that it took me about five years to get to this point.)
Some info that may be of help for you . . .
You may want to check into a Print-On-Demand service (NOT a "publish-on-demand" vanity press where you pay a company to publish your book, those are entirely different and are nothing but ripoffs). Print-on-demand uses a high-resolution laser printer to print and bind one copy of a book at a time from a stored computer file. It produces professional-quality printed books (indeed many of the professional publishers have been moving their backlists to print-on-demand so they don't have to pay for offset print runs). Print-on-demand does each book to order, so instead of paying upfront for a print run of hundreds of books, you just pay one at a time for the ones you need. It's a godsend for small publishers.
There are three options available to small publishers for print-on-demand. One is Lulu.Com . The advantage to Lulu is that you don't need a publishing company of your own--Lulu does all the ISBNs and that sort of stuff, and Lulu can (if you purchase their distribution package--though I think they were changing this to include some sort of free distribution) list books for sale at Amazon. The disadvantages with Lulu are that their printing price per book is a bit higher than everyone else, and that all their books are clearly marked as published by Lulu, which severely hurts their sales (most people still view "self-published" books as crap). Lulu is good if all you want to do is print your own professional-quality books for sale yourself to friends and family. It's really not economical for distribution to the public.
A second option is CreateSpace, which is owned by Amazon. CreateSpace has a lower price-per-copy than Lulu does, and it lets you identify your books as being from your publishing company (whatever you want to call it) rather than CreateSpace. So when your book is listed on Amazon, it appears as any other publisher would (though the savvy people will know it's CreateSpace because of the ISBN number). The biggest disadvantage of CreateSpace is that it ONLY makes its books available to Amazon US, and it charges a setup fee for every title you do (that's how CreateSpace makes its money). CreateSpace's fee is less than Lulu's charge for a distribution package. CreateSpace is as good option if all you want is to have your book available on Amazon, and you don't want to set up your own publishing company.
A third option (the one I use) is a print-on-demand service called Lightning Source. Their printing cost per copy is lower than CreateSpace, and they distribute not only to Amazon US, but to all other outlets too---Amazon UK, Amazon Europe, Barnes and Noble online, Powells online, and any brick-and-mortar store that wants to order it. The big disadvantage to Lightning Source is that they do not work with individual authors--they ONLY work with publishing companies, and that means you have to set up your own publishing company, which includes all the federal and state paperwork to form a company, and you must buy a block of ISBN numbers--the initial cost for all that is $500 to $1500 depending on how many ISBN numbers you buy to start. But that disadvantage is also an advantage---with my own company and my own ISBN numbers, my titles look just like any other publishing company's titles--same quality, same listing on Amazon and other online bookstores. Financially, Lightning Source also charges a setup fee per title, and also an annual catalogue fee per title. But the much wider distribution makes up for that. For the serious publisher who wants to sell print books to the widest possible audience, Lightning Source is the best option.
And there is yet another route to go, which you can do either in addition to print books or instead of it---ebooks. Kindle (which Amazon owns) has a program called Kindle Direct Publishing which allows anyone to submit ebooks for sale at the Kindle Store. Submission is entirely free, and gets you listed just like every other listing on Kindle. You get to set your own price, and you get X percentage of every copy that sells. The big advantage for the Kindle ebook route is that it's completely free---you don't need any publishing company or ISBNs or setup fees or printing costs. The disadvantage of Amazon's direct publishing program is that it ONLY gets you on Kindle, not on other ebook platforms like Nook or Apple Books. But there are other places (such as Smashwords.Com) who can do that for you, free.
If you're going to publish fan fiction, of course, no matter which route you take, you'll also need to reach a licensing agreement with whoever holds copyright to the characters (or they'll sue the crap out of you). How much that will cost depends on the company--as you point out, some companies won't license fan fiction at all, while some, like Lucasfilm and 20th Century Fox, seem willing to work with fans. It's a big advantage for you if you can get the company to agree to a licensing fee of $ per book, rather than an upfront fee all at once.
But once again, I want everyone to go into this with their eyes open. Most books that are published, even by the big New York book houses, sell next to nothing. Publishers will find that some 80% of their total sales will come from just 10% of their titles. I'm on a couple forums with other small publishers, and only about ten percent of us are actually making enough income from publishing to quit our day jobs and make a living at it. So everyone starts out with the odds against them, and most of us never make it.
But as before I do encourage everyone to try. If you don't live your dream in this life, you won't get a second chance.
