https://thepointsguy.com/news/cruise-ship-muster-drill-changes-reasons/Not even sure how it would be possible to calculate the cost of either. The staff are already on the ship, so I would think the cost would be zero.
That was the reason why Disney went back to in-person muster…. Much less staff resources needed to conduct one thirty minute drill than station staff around the ship at all the muster stations for a 3 - 5 hour period. If you don’t do e-muster you don’t need as many CM on the ship — which means a reduction of expenses (which Disney has publicly stated they’re doing across the organization)….