Andorra has only one mobile network - Mobiland. As a monopoly, it charges a whopping €60 for its
prepaid SIM card which includes €60 of credit, and this expires after 7 months.
One way to get around this, at least for data, is to use a foreign SIM card such as Vodafone UK, which has always been one of the cheapest networks for data roaming, years before
Vodafone Italy and
Orange Spain started offering anything cheaper. Vodafone UK charges £2/day for 25MB/day but, according to
this page, it is soon going to exclude Andorra from its Europe zone, which, according to
this page, is because Mobiland has increased its wholesale charges. This being the case, I would expect others such as Vodafone Italy and Orange Spain to have no choice but to follow suit. If the wholesale charge is now too high for Vodafone UK to charge £80/GB, then it is unlikely that Orange Spain will be able to continue charging only €10/GB.
It appears that Mobiland is abusing its position as a monopoly to charge unreasonably high prices, both at a wholesale and retail level, which will soon leave visitors to Andorra with no choice but to be ripped off.