Dawn, I agree with you about the woman whose cheek began the thread - she's obviously taking the pee.
Ela, I don't like the idea of fixed donations, and would rather take on a cat who hadn't been MOT'd or chipped etc, and get these done myself. The vet is usually the first port of call for any new cat anyway. Paying £50 for two cats merely adds to the initial expenses of new cats, as I like to get them new bedding, toys, etc. rather than use those of my former cats (it saddens me to see old toys around, so I throw them out).
I have no qualms about paying for vets, as needed (Polly, bless her, is costing a fortune, but I don't mind), but I do object to the idea of BUYING a cat, which is what a fixed donation is: a purchase price. I don't pay to have friends, likewise I don't pay to have my furball friends, but I give them all the love and care they need.
It's a shame that more people who can afford it don't regularly donate to animal charities.