Like most people, I combined Moray with a trip to Maras (the salt flats). If you take a private cab from Cusco (which I recommend if there are 2 or more of you, because it's only $60 and a regular group tour runs $25 pp anyway), your whole outing should take about 5 1/2 hours.
It is interesting to realize the science behind Moray. The Incans (or pre-Incans) used this place for agricultural experimentation, because they realized that there were different micro-climates at each of the plateaus.
For a 10 sole admission charge, why not come here? It's a cool day trip. But let's not go overboard with the praise here, you're not going to spend more than 30 minutes at Moray, because after you take a few pictures and walk down to the bottom, there's really nothing to do here. It's just something to say you did. Unless you had an extra day to spare on your trip, it's not necessarily a must-see destination.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.