Hi, you can do the math, just by looking up the standard ticket prices yourself. The Acropolis Alone is €20. The combo ticket is €30 ... for Acropolis plus 5 other Ancient sites of varying interest;( Ancient Agora, Theatres of Dionysus & Attikus, Temple of Zeus, Hadrians library, and Kerameikos). Frankly, the Agora is worthwhile wlaking around in if u do a bit of research, the next 3 can be appreciated in a walk-by, and Kerameikos is too far, if you are only in Athens for a couple of days.
Your info is incomplete, so we cannot answer you. If you say "the Museum" and you mean the Acropolis Museum, its admission is just €5 so thats €20+5 -- and a charge of €7 to buy the tickets ahead for you. Not needful really in September, just be at the Acropolis box office (OR the entry to the South) at 8 or 8:15, no delays... this is not like Rome and the Vatican/Pantheon Sistine chapel lines or Paris & the Louvre. If the €32 includes the Nat. Arch. Museum (list price €10) it would be an OK deal, but y ou just say "museum," not plural.
BTW, as you may or may not know, as taxi service is not a guide service.... they're not allowed to take you inside a museum or ancient site and show you around, because they're not trained/educated/licensed guides. All they can do is hand you a brochure to use -- and also they can't drive you up close to many of the ancient sites because so many streets/lanes surrounding these are no-cars. So basically they are hired drivers who give you bottles of water, a nice line of patter as they drive, and take you to their uncles taverna for lunch. It's good to consider what you're willing to pay for this (€100? €200?) or whether it might be worth using a good map, and hailing an occasional street taxi to places that are a bit farther (i.e. the nat. arch museum). Many people, especially with limited mobility, do value this kind of taxi service; it's just good to know exactly what they can and cannot provide.