What gets me with the NRM and London's Science and Natural History Museums is the sheer number of staff they employ to extort a donation out of you upon entry and get you to fill out the gift aid form.
Is there anything left after the wages and other employment costs have been paid out of the donations?
I remember the NRM when it was truly free entry - you could just walk in, straight past the reception desk - no problem, no challenge. Plenty of collection boxes around where I always dropped a note or two.
Last time I went, there was a small army of staff shepherding everyone into airport style queues where you waited to be "greeted" by several pay desks, where the people were actually putting you "suggested donation" into a till. I was with a child and an OAP so I rounded down my "suggested donation" rather than paying 3 times the figure they suggested and the woman behind the counter basically asked for the extra, which I politely declined pointing out it was supposed to be free! It left a very sour taste.
At the Science Museum and Nat Hist museum, there weren't official "pay desks" but there must have been well over a dozen "gift aid" advisors at every entrance, virtually bullying everyone to donate and complete the forms.
The "free" entry was just another vote grabbing popularity stunt for Labour trying to buy votes. It was stupid and should be reversed so people pay again. Stupid to give free entry for foreigners who are willing and able to pay - even if they give a donation, they can't gift aid it. They should get back to charging the proper entrance fee for everyone at normal/peal times, and do free or discounted entry at quiet times or for schools etc. No sense in not charging for people who are able to pay.