How to get to Arendonk from Antwerp Airport. Is there any bus route? If I take a taxi, would it be cheap?

Answer 1

Google maps give the distance as 52 km, about 35 minutes.
That is not going to be cheap.

This is the site for the Belgian trains, it can give you door to door public transport information:
http://www.b-rail.be/main/E/index.php

I get about two hours for using public transport.
So it might be worth it to go by taxi if you can not find a better connection.