Thanks for reaching out with a question. It may be difficult to find current and precise data on this, given that there are multiple demographic groups on the peninsula. It would be appropriate in the context of this challenge to make some assumptions where information is hard to find, but be sure to link these assumptions to some reference points/context.
A few places you could go to gain more context on the economic situation on the Cape York Peninsula are below:
Australian Bureau of Statistics: These are quickstats from the last census (2016) which has information on median incomes & employment rates. https://quickstats.censusdata.abs.gov.au/census_services/getproduct/census/2016/quickstat/315011396
Also have a read of Chapter 2 of this report tabled in the Queensland government Economics committee. It is from 2011, but there is some still relevant information that will give you insight into the general context of the Cape.
Qld House of Reps Economic report
It is also important to consider the the cost of basic groceries, and the impact this may have on disposable incomes; due to a number of factors (transport costs, purchasing power of stores, etc) the cost of essential items is quite high, and this can take up a large amount, if not all, of a family/individuals income.
You can read more about that at the links below:
Article in the Sydney Morning Herald
Article in the Guardian
You could also read some of the submissions to the federal inquiry on food prices in remote areas here: Federal Inquiry into food pricing and security in remote indigenous communities
I hope this helps – if you’d like to provide further context to your question by letting me know which specific project brief you’re working on, I may be able to help you further.