It seems like a hefty and unnecessary expense. Like others have said, the Acropolis combo is €30. The only additional “advantage” this one offers is free public transport, thru the Hop on Hop off, which kind of limits you to its routes and timetables. The sites are all very reachable on foot; the bus would restrict you.
It seems a bit dubious, too, not only because the price seems inflated, but because it claims to allow you to skip the line ups (which weren’t that bad) to “the Acropolis and the Parthenon”. Well, once you get past the turnstiles at the Acropolis entrance, you’re “in”. There is no line up, per se, for the Parthenon. Makes me wonder.
I would pass on this one, and stick to the Acropolis combo.