Objectively Viewed, This Is Not So Straightforward
Whilst my initial instinct lay with the majority opinion here, I now belive that the issue isn't quite so straightforward.
On the one hand, there is case for ensuring our MPs receive a salary appropriate to the standing we believe we want to hold them in. Pitching that at mid-level SO1 level seems about right in my opinion. Aim lower than that and frankly you dis-incentivise a large swathe of suitable candidates from the role and leave the field clear for those of substantial personal wealth or those of lesser means but with an eye for alternative income streams perhaps at odds with the role. That said, the allowances and accommodation package is ripe for overhaul - I have never understood why MPs can't have exactly the same deal as MOD desk officers.
The big issue, though, is the perception of a big rise now against a back drop of austerity and public pay restraint. Not an easy one to square and frankly will need lots of spin to avoid the inevitable backlash. However, no matter how the issue is tackled, it needs firm and clear leadership and a strong narrative - either way. Sadly, these are qualities currently lacking in the Palace of Westminster.....