@NaturalMineralWater: I respect and appreciate your choice to serve your country. Your wife is alone raising three young children… I doubt you have any idea how difficult (mentally, physically AND emotionally draining) that is, and it is a 24/7 job! I raised my one son alone and sometimes thought that was more than I could handle – I can’t even imagine having 3.
As noted, one’s location has much to do with prices. I see California, Oregon, and Connecticut on your profiles. If she is in CT, the cost of living here in the Northeast is criminal. Are you certain that both you and she are speaking about ONLY food and not other health and beauty and household items?
Is she sending you the receipts for you to review, or are you just going by the total amount of the check/charge? Seriously – have her mail you a bunch of the receipts and go over them line-by-line. Since you have internet access, you might go on websites to price compare – just enter in the zip code of where your wife is living to ensure accuracy.
Since she is alone, I guess she has to take the kids to the store with her – she does not have time to stand there and read labels or compare unit prices – she needs to get in and out before someone has a meltdown or someone starts poking at someone else. There isn’t much that will make a person break a sweat faster than having crying, whining or bickering children in public places.
I appreciate how tight finances are these days, but I get the impression that you haven’t put yourself fully in your wife’s shoes. Please try to see things from her perspective; allow her to open up and vent about how tired and stressed-out she is. Work on respectful, empathetic communication, because right now, that is all you have.
Long-distance relationships are extremely challenging, and I understand that you wish you could be there to help her. But you can’t, and it seems that you might be trying to micro-manage from halfway around the world. If you develop a pattern of getting on her case about things, and she gets on the defensive, it will very likely carry over when you get home. Proceed with caution, and good luck to you both.