I think the condo fee there is, actually, very low. Not a sales pitch here either. Take a look at other buildings that have similar amenities (elevator, pool, gym, concierge) and you will see they are, at least, $300 higher. Not kidding. The only hook at Regatta is the parking, which stinks.
Taxes, you can't do much about. That is a city of Cambridge issue, decided by the assessor's office.