Like at the National Gallery or the Tate Modern, they have donation boxes and suggested donations (about £3 or something I think) - do you pay that? Or proudly stroll in based on the knowledge they are funded by your precious taxes?

Apparently some people in the USA are suing the Met in New York over the way they present their 'recommended' prices - but I don't get it, I was there last year and I'm pretty sure I just walked in like i would the National, no lines or anything.

http://gawker.com/5992235/why-you-should-never-feel-bad-about-not-paying-the-mets-recommended-admission-fee

Are UK galleries/museums as rich as that? Do they need my money? Can I just keep buying novelty pencil sharpeners in the gift shop?