Manging the Unexpected Costs

The Credit Crunch has an impact on the incoming invoices. I and other SOLO members have noticed an increase in unsolicited ones or larger ones. No, I don't mean those scams our clients get suggesting they should pay extra "registration" fees.
The ones that worry me are from associates. One letter begins "In the absence of your instructions to the contrary, we have reviewed the file ... and here is an invoice" It was small and I paid it.
Another problem is invoices for reporting office actions on long dormant cases. These can be awkward to pass on, but they pose a dilemma. What do I do with a Japanese office action with no invoice but no information either that would help make any decision. On the other hand a thousand dollars for a detailed report on a US trademark action creates a serious case of Bill Shock.
One method is to put in your terms of trade with associates that you cannot be billed without a budget for the work having been agreed in advance. I have accepted that restraint from one of my clients. They are smart. It does share the risk. I have to make a decision when I get an office action. I need to review the matter to create a budget. If it looks hard then the budget might be bigger than if the work had been done on the standard hourly rate but then again it might not. Even after all my years, getting a budget to match actual costs is a cause for celebration.
Another top tip is to avoid asking anything in the nature of an open ended question without a reservation that if the costs will exceed a specified amount please get clearance in advance.
Work creators will always rise up when work falls away. How do you ensure that you and your clients don't suffer?