It seems that the first version was seemingly too broad so I'm doing my best to make it more focused and answerable.
It is about making a domain model and I don't usually have a problem analysing a situation but economics is not obvious to me and I'd probably miss the most important factors at play.
I shouldn't have used to word simulation as that probably implied to those reading that I wanted to make something complex and realistic.
That isn't the case and the aim is a simple educational tool with parameters to toy around with that can be built upon.
So open to all suggestions to get this back on the rails. TIA :)