Ha! Easily done. Any encounter with my young niece Veronica usually results in parting with at least that much.
"Uncle Winston, I simply must have a new pair of shoes/gloves/new hat/new dress/bracelet/car to complement my new whatever-the-hell-it-was that Uncle Winston paid for yesterday! All my *old* shoes are just horrid!" etc...etc...etc...
Another very good way: Take my wife Penelope for a drive downtown. Poof! A Hundred and Fifty quid gone in a flash.
They obviously think I'm made of money.