Is it time to raise book prices?

I’m torn on this. I want to keep prices low, so that more people will buy my books. But I’m wondering whether I’ve got them too low. I don’t want them so low that people think that they’re lower quality.

Here’s the current breakdown:

BookEbookPaperbackFrozen Dreams$2.99$9.99Tinsel Rain$4.99$12.99Morgan Barod$4.99$12.99Tales From the Fermi Resolution 1$2.99$12.99Tales From the Fermi Resolution 2$4.99$13.99Ghosts on An Alien Wind$4.99$13.99

(Books can be found here.) Is it finally time to push everything up to $14.99? The e-books mostly look okay, although arguably they could go up to $5.99. I honestly don’t know.