I mainly shop at Aldi, Sam's & a local bulk food store run by Mennonites. Aldi is cheapest (except for milk, butter & cheese) but they don't sell everything and we prefer the quality of Sam's for some items. Milk alone more than pays for my Sam's membership! Other than the occasional kroger sale I don't chase sales or do coupons but I do keep a price book. Here's things that are generally cheapest for me to buy at Sam's:
1% milk $2.50/gal
Egglands best eggs $3.42/18ct
Butter $2.87/lb
DAK bacon $2.98/lb
Blueberries, frozen, $6.98/3lb
Boneless, skinless chick breast $1.88/lb
Nesquik $0.16/oz
Sugar $0.43/lb
Softener salt $4.54/40lb
Yeast, nuts, frozen strawberries, pepperoni, block cheeses, olive/virgin coconut oil, quinoa (some of us are gluten free), store brand pet food & horse feed, paper towels (members mark), toilet paper (members mark), bucket of generic laundry detergent, mattress, clearance clothes/shoes, contact solution, protein powder, lg can crushed tomatoes (throw in some spices for cheap spaghetti sauce), kitchen trash bags, pillows.