Is this kind of money to much to ask for?

My sisters in law have both emigrated years ago from South Africa. One lives in Australia, the other in the UK. Both their husbands are doctors. My mother in law still lives here in South Africa and is ill with Alzheimers. My father in law has secured a place at an old age home but cannot pay the monthly costs. We need R 4000 a month - which means 100 UK pounds and 200 Australian dollar per month – the rest paid by us. I have no idea whether the above amounts are a lot to ask for from them. They cry financial debt and no cash flow. What can you buy for 100 UK pounds or 200 Australian dollar? Is this really to much money to ask for?