The train from Amberg to the Central Station in Nuremberg takes about 50 -60 minutes. This is an hourly service. I can't find the price for this ticket online. And then you have to travel to the airport. You can use the U2 subway line to reach the airport in 12 minutes from the central station. Or you could drive to the airport (less than an hour) from Amberg.
The Air Berlin flight leaves Nuremberg Airport at 18:35 and arrives at Paris Charles de Gaulle Airport at 19:55. Both are in the same timezone, so a flight of +/- 80 minutes. This is a direct non-stop flight.
Returnflight 20:40 - 22:05
You could book a flight incl. tax for less than 100 euro pp. The price will increase as more and more seats are sold.
Lufthansa has one daily direct non-stop flight.
Leaves Nuremberg Airport at 14:00 and arrives at Paris Charles de Gaulle Airport at 15:25 (operated by Eurowings). For the other flights you have to change planes in Frankfurt or Munich.
Return flight 15:55 - 17:15.
You could also book this flight for 100 euro pp incl tax.
The tickets for the Air Berlin flight and this flight are both restricted (eg non-refundable).
Dates used 9 August - 14 August
Travel from Charles de Gaulle to
Disneyland Paris:
VEA Shuttle with stops at the hotels 16 euro/adult 13 euro/child
If you decide to take the Air Berlin flight the VEA shuttle won't be an option. Last shuttle at 20:00 (Friday and Sunday later).
The trip is +/- 45 minutes depending on traffic conditions.
TGV to Marne La Vallee
+/- 10 minutes from the airport 23 euro (earlier trains 36 euro). Last train 22:00
www.raileurope.com
RER B transfer to RER A
I think that it should be possible to fly plus transportation costs to your destinations at either end of the journey for less than 200 euro pp.
Travelling time depends on the method of transportation chosen and the connection times between the different parts of the trip.