MP's Expenses

There's a lot about this on t'internet with some saying the daily allowance is a good thing through to others stating it's bonkers.

My inclination is that they should have a list of the things that they can claim for, which should be paid out on the presentation of a reciept, pretty much as it works for the private sector;
1. Travel expenses (but not to their "normal place of work")
2. Overnight accomodation (capped to avoid stays at the Hilton)
3. Meal allowance (if they stayed away from home the previous night)

Beyond that, I'm struggling to see what else they could reasonably claim for.