Saudi Arab has a huge budget deficit that it is trying to fill.

https://sg.finance.yahoo.com/news/saudi-officials-reportedly-offer-freedom-095000659.html

Saudi's national budget is based on around USD$80 oil but the oil prices have been hovering at around USD$55 now.  Therefore, there is a significant shortfall in the budget.

How is Saudi going to make up for the shortfall?

By imposing a 70% confiscation of wealth on the arrested parties.