Pretty Thermal Lunch Bag Just £5.97 at Groupon (including delivery)

Pretty thermal lunch bags are reduced on Groupon to just £3.98 + £1.99 delivery = £5.97.

They're canvas bags with reflective aluminium inside to keep your lunch warm (or cool).

Comes in a big range of colours:

https://i.imgur.com/mslm9mm.png

If you order more than one you get a bigger discount too. There's limited availability so if you're interested best to get in there soon.