PS Now is fully integrated with the PS Store, so you can rent games directly from their Store page. Rental periods range from four hours ($3) through seven days ($6), 30 days ($8) and 90 days. ($15). All rentals are renewable if you want to keep playing, and many contain DLC packages at no extra charge.
Sony said it will be experimenting and gathering feedback on the service through the beta, so expect these prices to alter. For example, the company already plans to offer $2 four hour rentals. A subscription service is possible, too.