Re: Don't bother. @AC
That's really a low blow. For all the hassle they get, the constant travelling, the long debates that run into the evening/night, and the exposure they have to their constituents and their problems, most MPs are not in it for the money, and many of them care passionately about their constituents.
I don't know whether you follow your MP, but if you did, you would probably be surprised by how many days they don't get back home in the evening, or how readily they are prepared to talk to any of their constituents.
Rather than constantly being in hotels, they are allowed to have an expensed second residence. If their permanent residence is in their home constituency, then this second residence will be in London or the home counties. If they have been parachuted into a constituency, then it may be there (although I would like all MPs to actually live in their constituency).
Because they are often out of their constituency, they are normally allowed to run an expensed office with some staff there. Often, MPs top-up the running of their constituency office out of their own pocket, or have family members working for more hours than they are paid.
And like almost any other employed person, they are allowed to claim justifiable travel expenses and ad-hock accommodation costs when away from any of their residences.
So yes, they do claim high expenses, because they do things that need paying for. And, yes, sometimes the rules have been abused. But probably not too much now (cases in the media nowadays are mostly historical).
They do not join Parliament to make money, at least not while they are an MP. Mostly people do it because they want to make a difference, and precious few manage this against the political machine. If they get well known, they may make money afterwards by taking directorships or on the public speaking circuit, but I suspect that many MPs after they leave office either move into local government, find normal jobs or retire. Only a few make the really big bucks. Most just grow grey and disillusioned.