This is the final illustration for this project. It's hardly been changed since the last post; I just needed to clarify certain parts of the image, such as the hand exchanging the money, to make it clearer.
I also added more texture to the river by using crumpled bank notes layered into it digitally. I think this works really well especially as I kept the browny colour of the money - making the rive look more polluted. This image is in A3 format so I think it will look really nice when it's printed and mounted etc.