I note from the Financial Times this morning that George Osborne and his Treasury team have travelled to China by business class. To me this seems perfectly reasonable. I have to travel round the world in coach, unless I am fortunate enough to get the occasional upgrade to Economy Premium or Business, and there is a difference in the level of comfort.
Osborne and his team are there to represent British interests and to promote British trade with China (trade missions were rather neglected by New Labour). It seems to me that it is desirable that they arrive in as fresh a condition as possible and should also be able to work on the plane.
David Cameron has adopted a rather hairshirt attitude to facilities for ministers on the 'don't do as I say, do as I do' principle. On one level, that is reasonable enough. The old Government Car Service (now Goverment Cars) had become rather bloated. Incidentally, Geoff Dudley wrote an interesting history of it which I have seen in manuscript, but it never seems to have been published: Dudley
Some ministers need to travel by car for security reasons. For others walking or getting the underground might be more democratic, but it eats into the time they can spend on public business.
There is room for economies, but there can also be false economies.