When I switched to Vellum, I re-formatted that same book in less than a day for $10.00, minus my time. Even adding my time, the cost was way less than what that third-party formatting company had charged.
Last time I spoke to one of the Vellum creators, the company doesn't have plans to make a PC version. If you're a PC user, once again I suggest asking other writer-friends for their recommendations.
Promotion
Self-publishing inevitably includes book promotion. I recently read a wonderful self-published murder-mystery that a friend loaned me. When I looked up the book on Amazon, it had only 3 reviews! Excellent reviews, but I was surprised there were so few. The ranking of the book was 1,427,618, which is very low. What a shame the author didn't invest more time and money into promoting her book because she wrote a very entertaining, well-written story, which unfortunately isn't getting the attention it deserves.
Lessons Learned
For my first indie novel, I paid $200 for a book blog tour that never materialized. I count myself lucky as some writers have lost much more money to bogus/ineffectual promotion services. How did I lose $200? I didn't get 3 or 4 recommendations ahead of time; instead, I selected the first service I found. I tried to use common sense—the business owner was a multi-published author so I figured that person had the right background; the website was appealing...but I should have done my homework and asked for more recommendations.
Recommendations
Tasty Book Tours specializes in the romance genre (which includes the subgenres romantic suspense, romantic mystery, and so forth). Self-Publishing Review named it one of the top 10 book tours. Lisa Filipe, the owner, is one of my favorite people in "the book biz." When I sign up for one of her promo tours, I know the book is in excellent hands.
BookBub isn’t cheap, but book promotions reach a vast audience. It's not always easy to get your book accepted, but when it is, you'll enjoy the benefits. My romantic-mystery The Zen Man, which I gave away for free via BookBub, got thousands of downloads...and over 100 reviews on Amazon.
Kindle Nation Daily offers pay-for services similar to BookBub, but the options are in general less costly. Just like BookBub, Kindle Nation Daily submissions pass an editorial review for appropriateness, but their guidelines for acceptance aren't as stringent as BookBub, plus you meet the people behind the scene at Kindle Nation Daily (BookBub is more mysterious in that way). My personal experience has been that I usually get 25% (at least) more downloads at BookBub vs. Kindle Nation Daily, but the latter is friendlier, nicer, even easier to work with.