Allied: the United Kingdom; Central Powers: Germany.
The Allies had a lot more potential wealth to be spent on WW1. It has been estimated that the Allies spent $147 billion on the war while the Central Powers invested only $61 billion. Britain and its Empire on the Allies side spent $47 billion while Germany spent $45 billion.
"There ain't no such thing as a free lunch" expresses the idea that even if something seems like it is free, there is always a cost, no matter how indirect or hidden.
