Basically, in older contracts, authors were paid 50 % of the cover price of a print book for an e-book, even if an e-book cost substantially less. (futura.edublogs.org)
In terms of royalties, authors selling books in the First For Romance e-store will receive 60 % of the sale price of an e-book over $ 1.99 / # 1.99 / $ 1.99, and 40 % of the sale price of an e-book under $ 1.99 / # 1.99 / $ 1.99; 50 % of the sale price of a print book; and 40 % of the sale price of an audio book. (thebookseller.com)
Improvements in book production and distribution services may delay things, but there will come a point where ever - smaller print runs will push the unit price of printed books upwards, beyond tolerance. (about.ebooks.com)