I license much of my portfolio for commercial use at pixels.com, but if you’re independently published you’ll get a better deal by contacting me directly with the name of the piece you want to license either by email or through Loki’s twitter account.
The Self-publishing Package is my only Royalty-free option. At $50 US, payable through Paypal (or even Etsy, if you like), it’s less than a 6th of what a traditional publisher would need to pay for a Rights Managed deal with a 2-year limit for images.
(Note: I only provide a large collection of backgrounds, not a cover design and layout service.)
Follow the link to my Self-Publishing Cover Deal page to view the license terms.