Do you think I have been overcharged by the umbrella?

[lucyclarityumbrella]

As an aside, ask them to clarify what they mean by "Budgeted expenses". You claim what you've spent, no more, no less. Anything else is evasion.

I would also query the Advanced PBA, this is not something that should be coming out as an allocation from your contract rate, this is something that should be covered by the brolly.
Oh and if we are on that there is also the Holiday Pay, Rolled up holiday pay was outlawed in 2006 as it contravenes the Working Time Directive and should be accrued (although this is a contentious issue with brollies).
As for the budgeted expenses, I will be interested to hear what happens to any excess if the contractor does not spend the actual amount taken