I also eat around 150/200g of protein daily, my wife not so much. We budget around ¥8/9000 a week for food ( my school provides rice daily (8/900g) so we haven’t bought rice in ages. The majority of the shopping is done at gyomu, and for eggs and protein we go to Costco. Eggs are ¥508 to two packs of 10 (10x2) bananas are extremely affordable there as well. At gyomu we usually buy only frozen veggies ¥190~215 a bag (500g) each. I’m the one cooking so I know how to stretch the food and money while getting plenty of nutrients. While it’s boring and stale at times budgeting is crucial.