No, they shouldn't subsidise you at all. Most guests when coming for dinner do bring something along.
This is basic living within your means, they can afford to spend on certain things, that's fine. If you cannot, you can look in to ways of hosting a dinner the cheapest way. It is possible, you will just have to plan and shop smartly.
Just because they earn more does not mean they should always be the ones to spend, no one should expect that.
If you base friendships on what people earn, then good luck to you. Most people base friendships on the character of people, what their income is usually never of relevance. You can certainly be friends with those who earn better and those who earn less.
I think it's quite awful that you think this way to be honest. If you truly feel so put out and believe it's not something you can financially afford, then just explain that to them. But you cannot always expect to take, take and take.
There's plenty of advice out there and ideas to host dinner parties on a budget, it will just require some research and effort on your part. Perhaps spend less time focusing on the income of your friends and more time trying to learn of ways to get more out of your money in the long-run.