This past Monday, I had to travel by car between avenue Henri Martin and Stade de France (13km), a far shorter distance than travelling from the Northern half of Paris to CDG, with its EUR 55 fixed price.
No G7 available, so I had to take an UBER around 10AM and the cost was ... EUR 70
At 2PM, I took a G7 back to my point of origin, and the cost was ... EUR 23, including a EUR 4 surcharge.
I'll try to be better organized next time

and make sure I book my G7 earlier.