Hi Brandon,
Beckett has made some good suggestions. I'd also like to add LIDL as a recommendation. It is a hard discount store and it's prices, quite often, are often lower than DIA. The main difference is that DIA carries more well known national brands than LIDL. However the meat section at LIDL is really decent.
I recently sliced my weekly shopping bill in half simply by changing supermarkets and buying more store brand products. We now do our shopping at Ahorramas and spend about 65€ a week for a family of three. The biggest expense on that list is the 12 liters of milk that we buy each week.
Other than that, I would recommend Mercadona. Their store brand, Hacendado, is high quality and very reasonable in price. Beckett, what brand of contact lens solution do you use? I have always been a B&L Renu user, but have recently switched to the brand carried in Mercadona. After checking the ingredients list and finding it to be essentially the same, I gave it a try and have since switched. Price difference? B&L 11€ and Mercadona 5€.
For those of you who are big on specific brands but want to be cost conscious, check out the following blog:
http://www.jorgegonzalez.com/listado-de-marcas-blancas/. There is a list of the major national brands that manufacture products for various store brands.
Happy shopping!
:)Rebecca