In the context of £20 shop, twitter users might be interested in following the author Frank Cottrell-Boyce. Each year at Advent, his family lives a budget of £1 per person per day and absolutely nothing from the store cupboard except salt. It's a struggle and really highlights the implausibility of Jack's shopping hauls.
I realise it's a privilege that Frank can choose to do this, and it's done to raise awareness and funds for a charity.
By the time his family have had unseasoned dhal for 3days, you realise how lucky you might be to have a cupboard full of spices and a tin of assorted oxo cubes.
ETA - his joy last year when he realised that a local indy grocery shop sold spices in small amounts. Too late for 2019 budget, but hopefully for this year.