Accordingly, the Department is increasing the fee for processing such requests from $450 to $2,350. As noted in the interim final rule dated June 28, 2010 (77 FR 36522), the fee of $450 was set substantially below the cost to the U.S. government of providing this service (less than one quarter of the cost). Since that time, demand for the service has increased dramatically, consuming far more consular officer time and resources, as reflected in the 2012 Overseas Time Survey and increased workload data.

Cost of renouncing your US citizen to remove yourself from double taxation has gone up. Significantly. In the quote they state the amount of request has gone up significantly. Rather than figure out why people are upset enough to leave behind their citizenship, they just raise the cost.

Wouldn’t it make more sense to figure out why those people are leaving and see if there is a reason for the increase?

Then again governments are not known for customer service.
US jacks up cost of renouncing citizenship - GenevaLunch News