Fighters enlisted with the so-called Islamic State terrorist group now make about $200 to 400 each month, according to an alleged statement obtained by an observer group based in the United Kingdom.

But that's about half of what they might otherwise bring in. Last week, it was reported that members of the Islamic State were facing pay cuts as the financial realities of a dogged war effort begin to pose struggles for the group in Iraq and Syria.

Related: The Truth About Terrorism the Media Won't Tell You

Citing the Syrian Observatory for Human Rights, a group that collects information about IS, the Guardian reported that the extremist group had released a statement explaining that the "exceptional circumstances" fighters were facing in the ongoing war had caused them to "cut the salaries of the mujahedeen in half."

"No one will be exempt from this decision no matter his position, but the distribution of food assistance will continue twice a month as usual," the Arabic statement read.

Wikimedia, IHS - ihs.com

Rami Abdel Rahman, who heads the SOHR, told the news agency AFP that militant fighters in Syria would be docked about $200 a month down from $400, while the better-compensated foreign fighters would have their pay cut in half to $400.

The self-proclaimed Islamic State has aims to set up a kingdom of Islamic governance, or caliphate, in the regions it controls across large swaths of Iraq and Syria. So far, the group has the makings of at least a nascent state, with laws, courts, currency, schools, and government institutions — all of which are filtered through an extreme interpretation of Sunni Islam. One example of the group's many perverse laws emerged in December, in the form of an apparent official notice outlining the rules of sexual relations with captive women.

Related: ISIS Is Literally on Drugs

The price cuts may come as a surprise, as IS is well known for its deep wells of income: oil, extortion, and the sale of prized historical and archeological artifacts on the black market. By some estimates, the group makes more than $2 million each day just from the sale of oil harvested from fields in areas it controls. The group is thought to make nearly half of its money from oil, accounting for about 42 percent of the $80 million it takes in monthly, according to a December study by the Information Handling Services Conflict Monitor. The other half comes reportedly comes from confiscation and taxation of the people living under the group's control.

Here's a graph from CNN Money that shows the group's main revenue streams.

CNN Money - cnn.com

Other evidence collected in a CNN Money report indicates the group brings in impressive sums of money, about $2 billion in 2014 alone.