Off to Paris today into ORLY. Staying in Bercy village.

Public transport would be easy I think but I hear that the ORLY monorail thing that links airport to the metro system is eye wateringly expensive. Apparently it only takes a few minutes from west terminal to the station, and is a driverless monorail (I have in my mind something like the LGW shuttle system).

I refuse to be taken the p*** out of by the French if indeed this thing is a rip off.

Are there any alternatives? Someone mentioned there is a bus service to Denfert Rochercheau, from where we can take one metro to our gaff at Bercy.. I assume this is cheaper but again can't find any fares online?

Or how much would a good old sherbet be from ORLY airport and how long would it likely take?

Thanks in advance