Simon asked how to say "superfaturar" in English and his question reminded me of overrated and overpriced.
Overrated:[usually passive] overrate somebody/something
to have too high an opinion of somebody/something; to put too high a value on somebody/something
In my opinion, Hirst's work has been vastly overrated.
Overpriced: too expensive; costing more than it is worth.
Fonte: Oxford Advanced Learner's dictionary