I thought I was being conservative at £150 between two people a month. I literally couldn't survive on 100.
I could on my own, but not for two people. I just made my lunches for the rest of the week (on holiday so no making staff meals ) and did a price breakdown.
4 Portions
Chicken - £1.25 - 8 drumsticks - 936 cals
Carrot - 10p - One large - 80 cals
Red onion - 15p - Half - 40 cals
Beetroot - 34p - Half bag - 120 cals
Quinua - 67p - 200g dry - 780 cals
Stock cube - 5p - one - 10 cals
Feta - 60p - 100g - 264 cals
Spinach - 45p - 1/3rd bag - 10 cals
Spices - 10p - Spice blend/harrissa
Dressing - Honey/Oil/Lemon Juice 30p - 100 cals
Total - £3.91 - 2240 cals
£0.98 per portion, 560 cals per portion.
I think £3 per day, per person if you cook everything yourself is totally doable. But £1.58 is really low.
Edit: Of course you could buy a ready made pie or something for a quid with a similar calorie count, but it's going to be way worse for you.