I think we should all pay a bit more with those earning more or spending more paying more.
As a higher tax payer I expect to be hit harder than someone on lower wages so a sliding contribution seems sensible. As would an increase on tax for non essential items.
The way I see it is that everyone earning should contribute but on sliding scale. And if you have the money to buy a new car, sofa, holiday etc then again paying a bit more on top is justifiable.