Where does Mojo Jojo keep getting his materials to build his machines from?

So, in the PPG Movie, it's explained that Mojo tricked the Powerpuff Girls into helping him build his lair and machines. They do so by gathering/salvaging materials, like a meteorite and a sunken submarine.

The film also explains where Mojo gets his electricity, from thermal energy produced by the volcano.

My question: Where does Mojo keep getting new materials to build new machines from? He no longer has a trio of super beings to help him.

Also, where did some of the other monkeys get the stuff for their machines?