My problem with the 50 cent outlets is that the contacts do loose their spring-action over a short period of time.
The Cooper blue-backs aren't as bad as the equivalent "residential grade" Levitons that Home Depot sells. Those REALLY don't last at all!
I saw the 50 cent Levitons used in an office/institutional environment that was renovated about four years ago.
Shortly after it opened, some of the sockets were already broken in half and dangling inside the box.
I prefer either the spec-grade Cooper grey-backs or - even better - the ones made by Bryant/Hubbell, when I can find those.