Media: The Real Cost of Digital Radio

This is Naustdal, my home village on the West Coast of Norway.
My mother, who still lives there, can receive 5 radio stations via FM or over 20 via DAB. 

Digital radio is very expensive. Or at least so we are usually told by wannabe experts. I have previously shown that is not the case. To build a DAB+ network from scratch is actually cheaper than staying on FM. But what is the real cost of building digital radio in Norway?