Your MUA prices are in line with OVO which I use.
You: 30p / unit, 23.5p daily standing charge.
Me: 27.7p / unit, 55.88p daily standing change.
Quit winging, put on a jumper.
Aldi would already be on the rock were the company at all interested. Which big retailer is really interested in an island with the population of a decent town in the UK? So Tesco is more expensive - this is the joy of living on an island with expensive freight links.
And did not Tesco state that prices on the small rock would be a few % higher than those on the big rock?
5% difference to replace Shoprite is worth the price.
Aldi stocks a minimal range of items so a full comparison isn't possible.
As for brands when you enter a store , there can be quite a cost to the supplier but with local produce it may be waved. Only Noa etc. can tell you if they are paying more.
I doubt I buy even 200 different items in the course of a year, let alone 500. My local supermarket is ASDA, their Just Essentials range is excellent value.