If you choose to fly from Charleroi, this is what you are looking at as extra costs (information of december Protected content a trip in January Protected content the holidays):
If you go by car it s a 60km drive one way and parking at the airport is minimum 15 Euro per night. I couldn't check the price because the website of the airport seems to be continuously producing errors today. ( Protected content )
Taxi Verts charges Protected content for one leg to Charleroi Airport or Protected content for the round trip.
The people from Airportways ( Protected content ) who claim on their landing page to be "the only non-stop door to door minibus service from less than 13 euro per person" actually charge 29 euros per person and per leg.
The shuttle bus from Brussels Midi is 13 euro for a single and 22 euros for a round trip: Protected content
It is also possible to go by train to Charleroi and then take a city-bus (Tec) from Charleroi train station to the airport (about 25 min). I don t recommend this because the travel and transfer times make this a real adventure and it will cost Protected content too.
Hope it s of use to the InterNations Community,