Eating on a budget - could an online service help?

We've recently been doing a long term analysis of where the $'s go, and how to cut down on unnecessary expenditure. If you don't go out shopping or buying online it's still pretty hard to save money as most of it goes out in automatic payments for the Mortgage, insurance, rates, and utilities.

Food is therefore an obvious area to try and cut down on. Here's a few tricks that I've been trying.

Based on the Martian and some dietary advice it is possible to survive on Potatoes, Porridge, Kale and some fish and meat. E.g. http://www.sbs.com.au/food/article/2016/02/19/can-you-survive-eating-nothing-potatoes

We've been able to buy large bags of potatoes and porridge from Costco. Baked potatoes are yum (just poke a few holes in them with a skewer and cook in the oven without peeling them). Our garden produces some Kale and Spinach.  I like Vegemite (vitamin B), and I've been making bread and savoury muffins from scratch cheaply (corned beef leftover muffins are odd but tasty).  Beer can be made at home to (The English Navies built the canals just on beer).

Coffee is harder. My current solution is to buy green beans in bulk (only about $10/kg) and roasting them on demand (I use a Wok on the Wok burner of an outdoor BBQ, you have to keep them moving and watch and listen but I can produce fairly consistent results). 

I also wonder if an online service/store could help with this problem? E.g. if you only have $x/week to eat on and y people to feed, could an online service help by finding a mixture of foods and quantities available for this amount that would provide the required calories and nutritional value for that number of people for week, and then delivering it to your doorstep? (Given that running a car is also an expensive option on a limited budget)? Does they already exist? What would a business model look like for this sort of service?

While in the UK for a year in 2004 we used a grocery box service (delivered). This was handy as we didn't have a car, and supermarkets were expensive and a long way from where we lived. It was also good as you could plan means and there would be weekly cheap products that were in season. 

There's is a lot of food thrown out in Australia (about 1/2?), some of it even before it's send to the supermarkets. E.g. Bananas have to be a certain size, shape etc for most supermarkets to purchase them. Who cares!!!! 

PS This page suggest eating some sweet potatoes to!  In NZ these are called Kumara - yum. My Dad loved these. And I liked them as Wedges. 

Here's a recipe for Kumara and Peanut butter soup!

One of my favourite Tagine recipes involves Potatoes. 

I've also found that it works for very cheap cuts of lamb (e.g. cheap shoulder lamb chops or even lamb neck) as they are slowed cooked. You can also just add any vegetables you have spare, including cauliflower, broccoli and chillies.  Sometimes you can get cheap Eggplants from the "ugly" vege section of the supermarket.  You could even make a vego version of this, maybe use chickpeas instead of the lamb...