SecondComing -
stock cubes - I buy in bulk from Approved Foods, they usually work out at 1p each or less.
olive oil - only buy a bottle every couple of months and then whatever is cheapest, for normal use I buy a huge bottle of veg oil in with the shopping when I need it.
bisto - don't buy it, gravy from stock cube, cornflour and water
peppercorns - usually buy cracked pepper in a huge tub online which lasts about a year.
tampons - dd and I use Asda's own brans 3packs for £2 or something like that which comes in with shopping
salad cram/mayo - seldom buy it because the kids don't like it. Buy from Approved Foods occasionally, usually 3 jars for £1
HP - again don't buy very often as only I like sauce in here
plasters - buy as needed, surely people don't need these every week?
calpol - don't need it, but used to get equivalent from pharmacy free under Direct Care
paracetamol - costs about 20p in the supermarket
jam - make my own with foraged fruit in the autumn to last all year.
Spices come in huge packs from either online or the ethnic food aisle.
Honestly, I promise that you can keep shopping bills right down. It takes a lot of planning and changing expectations to begin with but the longer you do it, the easier it gets because you are used to it.
What I buy from AF other than crisps/biscuits - A while ago I bought enough beans/lentils/chick peas to last about a year, they were on offer at 4 packs for £1 and keep for ages. Recently I bought a load of polenta: a load of bulghur wheat; tomato ketchup and HP sauce; mayonnaise; huge tins of plums, mandarins, peaches, different beans and tomatoes; stock cubes; poppadoms; hazlenuts and peanuts for nut roasts etc; tinned crab 12 tins for £5; tinned lentils 12 tins for £4; spicy tomato pasta sauce for DH 6 jars for £2, stock cubes 5 packs of 20 knorr veg cubes for £1, 1kg of beef bouillon powder for £1, 2 cases of those tubs of tropical fruit in juice for £1, instant custard 10 packets that make 1litre each for £1 ... Last year they had 5kg bags of pasta for £1.50, so I bought some of those, also 3kgs of semolina for £1, things like that.
It all depends what they have. Obviously, I also buy some snacks from there because they are much cheaper, but it's a once a month thing and when they are gone, I don't buy more.
OP, AF do deliver to Ireland but there is a similar site called Food Bargains that is actually based in NI that is always worth a look.