Amazon has some Orbit novellas on sale for $0.99 (regularly $2.99). Here's a search that should find them - just scroll past the free samplers:
Here's a few of the titles:
The Butcher of Anderson Station: A Story of The Expanse - James S.A. Corey
Gods of Risk: An Expanse Novella (The Expanse) - James S.A. Corey
Perfect Shadow: A Night Angel Novella - Brent Weeks
Spirit's Oath: An Eli Monpress Novella (The Legend of Eli Monpress) - Rachel Aaron
Blooded: A Jessica McClain Novella - Amanda Carlson
At $3, I think these were overpriced, but for $1, I'll probably bite.
I think they're probably on sale elsewhere, too.