I would definitely give Lidl ago rather than Sains basics.
I now do our main food shop at Lidl every week after we got very short of cash and it has literally halved our food budget without trying to scrimp at all.
You can't get a few things there that we need so have to stock up every now and then (e.g. barley,polenta, pomegranate molasses, saffron, stuff like that).
Last night for tea we ate wholemeal pitta, homous, tabbouleh, fattoush and leftover meat from the sunday roast.
I know the Lidl prices for things as I have to be careful with money at the moment. Just for interest I went on my supermarket.com just now and looked up the sains prices:
wholemeal pitta bread 70p sains, 39p lidl
homous 110p sains, 79p lidl
tabbouleh- parsley 80p sains, 49p lidl
(mint from garden)
spring onion 75p sains, 39p lidl
1 large beef tomato 80p sains, 36p lidl
1 lemon 30p sains, 30p lidl
burgul- don't sell in lidl, buy from sains or middle eastern deli once every 3 months or so, can't remember cost)
fattoush: cos lettuce 100p sains, 80p lidl
cucumber: 80p saisn, 49p Lidl (on sale this week, think its normally more)
(also used some of the lemon and half the tomato from the tabbouleh)
sumac (again, can't get at lidl, we buy from a middle eastern deli)
(Obviously also used olive oil, salt etc in small quantities)
(Lamb: leftover from roast and from freezer, can't remember where from now)
Now we didn't use everything, obviously, we have leftover half the cucumber and lettuce to use in another meal as wel as half the homous for sandwiches etc so a cheaper meal than the costs would show, but in terms of cash paid, last nights meal cost us 401p in lidl and would have cost 625p sains
This looks like it would reduce the spend by 1/3rd per week if scaled up but we have found it to be a bit more than that because we also don't buy as many treat type things that aren't available at lidl like roasted artichokes from the deli counter etc