Actually proved a lot easier than I thought, Doug. Arguments deployed included:
1. "Think of it as an early Christmas present."
2. "It's a one-off...I'll never ever do it again."
3. "You spent over two hundred quid on clothes last month." (The latter did not prove a particularly promising approach and I quickly abandoned it.)
4. "If I don't and they go to the wall, you'll have to put up with me whinging on Saturday afternoons." (Many thanks to Baggy for that particular stroke of inspiration).
Result!...and, yes, I know, my share won't be worth much and I won't have any voting rights and, as a season ticket holder, my flexi-tickets will be sod all use...but, symbolically, at least, I'll have a little piece of Stanley!
