In the area of Cathays you can find lots of supermarkets, however the cheapest one is Lidl. It is located next to Cathays railway and Cardiff University. It is true that depending on what part of Cathays you live, you'll have to walk a long distance, because there's only one Lidl. However, I think it is worth it if you want to save money.
There are other supermarkets as Tesco or Sainsbury's, but there are expensive. However, it is true that if you are in a rush and one of them is right next to your place, you'll go there.
MO-SA: 8:00 - 22:00
SU: 11:00 - 17:00
It depends on the commercial establishment, but it opens earlier and closes later than Lidl.
- Sainsbury's Local: 7:00 - 23:00
- Sainsbury's: depends on the commercial establishment.
In the city centre is where you can find the commercial area (Queen Street). There are a lot of clothing shops such as Zara, Top Shop, Primark, New Look, etc. There's also a shopping centre (Saint David's), where you can find anything you need.
Moreover, there is an app called "UNIDAYS", where you can get discounts.
Poundland is a shop where you can find almost anything you need for 1 pound: food, stationery, cooking utensils, etc. You can even find items cheaper than in a supermarket. I strongly recommend you to stop by!
If you want a good latte or coffee, you must go to PORTUGUESE BAKERY in Castle Street. They have the best coffee and pastry in the city, and the price is affordable.