[gottareply2020]

Llyod’s of London released a report in May 2013 on the potential effects of a significant Coronal Mass Ejection (CME). The projected costs were 0.6 - 2.6 Trillion USD.

https://www.lloyds.com/news-and-risk-insight/risk-reports/li...

As other comments have said, the biggest pain would be the availability of replacement small transformers.