Open Road titles are often heavily discounted on Amazon though. I don't really keep track of the epub stores, but if there's a title I want on Open Road, generally speaking I just wait a while and eventually it's available for cheap on Amazon, even if only temporarily.
For example, I just picked up Nebula Award-winning Babel-17 from Amazon at $1.99 as a daily deal. Not sure if that originally came from E-Reads or not, but it's definitely Open Road now.
Of course, that doesn't cover the concerns about geographical restrictions or DRM.