Buy TheSun newspaper today and you will find a 15% off voucher when you spend over £50. (http://www.hotukdeals.com/item/280375/15-off-everything-when-you-spend-50/)
This would make Henry £72.25 + 30p for TheSun = £72.55.
Don't forget to use you Homebase Spend'n'Save card.
And finally you might wish to buy other items as you would get 15% off everything now that you are spending over £50.