THE ONLY OTHER ROBOT I KNOW PERSONALLY IS THIS GUY AND AS FAR AS I KNOW ALL HE DOES IS WATCH TV AND OCCASIONALLY KILL PEOPLE. I DON'T THINK HE DRINKS.
"All Systems Red" by Martha Wells (A Security robot gains sentience; fights an evil corp, mostly just wants to watch its shows in peace)
"Six Wakes" by Mur Lafferty (Clones on a colony spaceship wake in new bodies to find their previous bodies murdered, and a disturbing gap in their stored memories. They have to find out who murdered them and sabotaged the ship.)
"Persephone Station" by Stina Leicht (Criminals on the run take a job to protect an unknown sentient species hiding on a sparsely-populated planet.)
"Dead Silence" by S.A. Barnes (A salvage crew finds a long-lost luxury cruiser; when they go aboard, they find every passenger and crew member had died horrifically. As they begin to search the ship for salvage, they start to see and hear things that make them wonder if they will fall victim to the same madness as the dead. Space horror, yes, but not fantasy.)
My novella recommendations:
"All Systems Red" by Martha Wells (a security android gains sentience; mostly wants to just watch its shows in peace)
"When the Tiger Came Down the Mountain" by Nghi Vo (a historian and their guide get trapped by three tigers who can talk. They survive the night by telling stories.)
"Hammers on Bone" by Cassandra Khaw (Hard-boiled Private Detective gets hired by an 11 year old to kill his stepfather, who's a monster. Literally.)
My husband says that if you feel up to a novel size - but you'll get hooked right away! - try "Old Man's War" by John Scalzi.
I don't sell anything for less than 2.99. I don't know much about action/thrillers, but in SF/fantasy, publishers are starting to market novellas like novels.
Look at Martha Wells' <em>Murderbot</em> series, novellas, all. The first is 3.99, and all subsequents are 9.99. Oh, shit, the 5th one is 13.99; this has really taken off. My point is, they are pricing novellas just like novels.
I think you can't just write a book and publish it on Amazon and see what happens. Because if you do it like that, nothing will happen.
You want to research your genre and find a market. You need to find out Amazon's subcategories for your genre and see how each is selling. There will be a couple hot categories where the competition is fierce, and there will be some cold categories. You want to find a category somewhere in the middle that syncs with you and what you like to write.
Then you want to research the books that are selling in that category, and emulate them. Readers are jonesing for a fix, and they want a certain type of narrative that's going to satisfy their particular craving. You want to have a cover that tells your readers instantly that you've got what they're looking for. If you're no good with a graphics editor, you can buy premade book covers for ~$30-100.
Why do you think it's too short to self-publish? A piece of fiction is as long as it is. When you self-publish, you're not limited by needing to fit into anyone's target word counts.
Lighthearted, upbeat SF and fantasy is hot right now, and people are buying novellas. Look at Martha Well's <em>Murderbot</em> series. All novellas. The first one is $4, and after that, they're all $10. And they're selling like mad.
Clean up your novella and generate a final draft. Write your blurb, slap a premade cover on that thing and post it to Amazon.
BTW, in self-publishing, it's best to write a series, because that way every book is a promotion of the rest.
Man, I really liked All Systems Red, but in this economy, I feel like I can't move forward on this series until we get an omnibus edition of the four novellas, which currently go for around $10 a pop (minus the first one, which is on sale on Amazon right now). Apparently, it's a possibility, but there's no ETA.