Via /r/PS4, the email addressed to PlayStation Now beta testers tells them about the program moving into Open Beta phase on July 31, 2014. Then, it mentions of slew of new titles being rotated from the old. What separates the newly available PS3 games to test out from the old is that PlayStation Now beta testers will have to pay to try them out. "These prices are ultimately decided on by the participating developers and publishers," the email states. "Your feedback during this next phase of the Private Beta is extremely important, as we will be monitoring it closely."
Kotaku has a sample of some of the game rental prices for PlayStation Now. To play "Guacamelee," one could pay $2.99 for four hours, $5.99 for seven days, $7.99 for 30 days, or $14.99 for 90 days. Considering the PS4 edition of "Guacamelee" will costs $14.99 to buy (and includes more goodies not found in the PS3 version), it's ridiculous that PlayStation Now charges the same price for a three-month rental. During the Open Beta, game rental prices for PlayStation Now will range from $2.99 to $19.99, as it expands its library with over 100 titles.
With nothing set in stone, Sony emphasizes these prices are not finalized. PlayStation Now beta testers are encouraged to share their thoughts on the official message board or through email. As posted on Reddit, outsiders wishing to share their thoughts to Sony on PlayStation Now rental prices can do show at firstname.lastname@example.org.