Expenses or perks?
All this kerfuffle over expenses (and as scandals they vary from the properly corrupt to the pruriently amusing) is there because there is a cognitive disconnect between what MPs think they are worth, and what they are paid. £65k might seem a helluva lot to most people, but it is (or was, lets see how salaries stand up to the current mess) entry-level stuff for big City jobs. Accordingly MPs have been used to treating allowances (and remember that's what they're called, not expenses) as a top-up to salary, and not as a way of reclaiming genuine business expenses. That way they get their effective salary up to a comfortable six figures, and look at the money getting paid to civil servants and quangocrats as a parallel. These fellas are on more than the PM - three times as much as a backbencher.
There are three ways to deal with this. We could raise MPs salaries to, say roughly the average claimed at present (about £120k?) and then abolish all forms of allowance, introducing the same sort of business expenses as currently operate in business. Alternatively, we could abolish allowances and introduce expenses as above, but make MPs make do with £65k a year. Or we could leave the allowance system as it is, police it better and hope that MPs realise that they're taking the mickey.
The first option is probably the most sensible, which is why it is the least likely to happen. The second would be the most popular with the public, and the least popular with MPs, so that probably won't happen either. So we're stuck with hoping that everyone plays fair and the problem goes away. Good luck with that...