Short stories and novellas:
Dragonswan by Sherrilyn Kenyon is avaliable at
Sony and
Kobo for 1.99
Dark Descent by Christine Feehan is available at
Sony and
Kobo for 1 dollar
Dark Dreams by Christine Feehan is available at
Kobo for 0.99
Novels:
Magic in the Wind by Christine Feehan is available at Sony for 1.99.
The short stories and novellas isn't US only since I could buy them. I suspect that the novel is, though.
Disclaimer: BN and Amazon probably have them too, but I haven't checked.