Overall, Japan is a very expensive country. When people ask me what is cheap here I always say chicken breast and alcohol. I get some strange looks, but other than some seasonal fruits and vegetables, this is typically the case.
Let's take milk for example. If you shop at the local grocery store a liter of milk will cost anywhere from ¥180 - ¥240, depending on the type and brand. It would take 4 liters to make a gallon (technically 3.79 liters, but you have to round up), so if you buy the cheapest milk it would run you about ¥720 ($7.50) for a gallon of milk. Juice would run you about the same, sometimes cheaper if you find it on sale. On a regular day an apple will run you ¥128 each, but to Japan's defense, the apples are almost the size of a newborn's head. A steak will run you at least $10 each. Everything is sold in smaller sizes so you pay a whole lot more in comparison to the United States.
Luckily we have a Costco about 30 minutes from us. It really is a life saver. While in the United States we only bought a few items at a place like Costco, here we buy almost everything. That gallon of milk costs me ¥476. I can get four nice steaks for about $26 USD. Fruit, produce, household items, all much much cheaper. And Costco does carry a few United States products as well, although you do pay a premium price for them. Diet Dr. Pepper will cost you $10 for a 24-pack and a box of 48 Crunchy Granola bars (one flavor and the only granola bar to buy here) will run you $19.
If you live here and switch to Japanese items and products (cereal, flour, sugar, cleaning, health and beauty items, etc) you can save money. However there are some things just not carried here or there are some items that we are "brand married" and we have to order from the United States or go to an International Food store to get. Those items have a large price attached to it. For example, I can get Gold Medal flour at Foreign Buyers Club. A 5 lb bag will cost me ¥920 ($9.50). A box of mac and cheese is ¥274 ($2.90). Those items that just can't be found here, such as any cereal but frosted flakes, I can order from the United States. That cereal will run me a cheap $8.00 and up per box.
Now that chicken breast and alcohol. Almost 6 lbs of fresh chicken breast will run me less than $6.00 per bag. A bottle of Absolute Vodka will cost me $13.50 ($22 in the states) and today I bought Cointreau for $18.00 (this is almost $40 in the states). Needless to say we have a very well stocked freezer and liquor cabinet.
I have been here long enough that I have lost all sense of the concept of price. And unless you have some quick weight loss tips for cooking with lots of tofu and weird fish, we don't have many options or alternatives here, so we just have to buy and pay the price. After not being back to the states for almost a year, I think it will be very interesting to go back to the grocery store this summer and shop. And when I move back for good, I may just die at the checkout counter from shock at how much I bought for less than what a small basket will run me here.