DD brought home a letter for a school trip
Ridiculous amount Loads of money
But it's for her favourite subject and is a GCSE field trip 
So I worked out how much a month & sent deposit plus 9 monthly cheques to cover the cost
Sorted
Then DH got some unexpected money most of which went of debt repayment, but we thought we'd pay for the trip which we did (& we got the previously post dated cheques back)
But if we hadn't had the 'spare/unexpected' money t would have been really hard to find all that money & 'GCSE' makes it seem necessary
Rant over