I think you just have to accept that some people really don't want to try. They don't want to spend money, they don't want to make an effort, they just want a magic 'fix this' button to be pressed. It's unfortunate that sometimes that attitude affects the welfare of their family or pets.
I don't believe that people who have money to spend are necessarily less likely to spend it, or less likely to make an effort. Some of them do, some of them don't. There are some people who make huge efforts on no cash, but others... well it's easy to say 'If I had the money I'd...' when you are never likely to be called on it.
I have found in business as well as rescue, that there are some people who will always jib at paying money for a good job done honestly and well, and those people will often create endless inconveniences for themselves, refuse to take advice and sometimes end up spending more or giving themselves more (expensive) hassle in the long run.
All you can do is help the people who actually want to be helped and don't let the rest of them take up more of your time and energy than you can spare.