Here are a couple more links to eating well on the cheap. Not specifically low carb, but most of the basic ideas can be adapted.
The Destitute Gourment - www.destitutegourmet.com
Simple Saving - www.simplesavings.net/
The $21 Challenge - www.simplesavings.net/21
I checked out the book The $21 Challenge at the library yesterday, and it has some good stuff in it. It's pretty much what I already do for purposes of this blog. I do my menus for the first three weeks, based on what's on sale that week and what's not on sale but reasonably cheap. My menu sheet includes the cost of everything I eat. My excel workbook includes a price list of everything I buy, including things on sale and not on sale, and also a sheet of pared down recipe info with prices. So I know how much a serving of whatever is when I put it on the menu sheet. I try to keep the cost of each day's food below $3.50, and as you've read in the weekly menu posts, they usually average around $3.20 - $3.40. This keeps my costs fairly reasonable. What it doesn't address, though, is what I actually spend. It's the staples that make this Challenge so challenging.
The way I set up this Challenge for myself, I start over each month with absolutely zilch. My purpose was to see whether I could plan a month's menus that cost no more than the average food stamp benefit received in Indiana per person in 2011. That comes out to $125 for 28 days. (It's easier to do 28 days than to fiddle with those extra days each month, so I scaled back the actual benefit accordingly.) This means that each month I have to buy the staples like a bottle of oil, and spices, and a jar of mustard and things like that that would really last for months or, in the case of a bottle of vanilla extract or worchestershire sauce, years. And these things usually run $15 - $25 per month or so, which I'd much rather be spending on more meat and veggies. But the "rules" are the rules, and so it goes. If I were following these menus in real life I would take the money that I didn't spend the second and third, etc. months on the staples and stock up on great bargains and use the rest to add more salads and other veggies. $10 a month would really help in that department.
So back to how I do this and how that relates to the $21 Challenge. I've just "bought" food for the first three weeks, keeping the cost of my meals to around $3.30 or so per day, but not keeping track of what I "spend." Once I've posted them here on the blog, they're done. I can't go back and change them. Before doing the Week 4 menus, I make up my shopping list for the month, recording everything I purchased, how much of it I used, and how much I have leftover to use on the Week 4 menus. So I might have a few servings of something I made for an earlier week, or half a head of celery, or a few chicken legs, or whatever. And I know what herbs and spices and seasonings I have on hand, how much butter and eggs and cheese and mayo, etc. And how much money I have left to spend for the week. This is the part that is similar to the $21 Challenge. Then I make up menus for Week 4, using up what I can of what I have left, and limiting my spending to whatever money I have left. Week 4 gets to be very challenging! It seems like I have quite a bit of food leftover to use, but it doesn't necessarily make a week's worth of meals. That's where I have to get creative. It's challenging, but fun.
Anyway, that's how I do my menus for this Challenge. For Weeks 1, 2 and 3, I make out my menus one week at a time, making sure that the cost of the meals is within my limit. Then I enter them into the Food Tracker here at SP and make sure that they fit within my nutritional limits, adding or moving around as needed, and still keeping my costs where I want them. Then the real work of the challenge is in Week 4, when I really work hard to use up what's on hand.
Just thought I'd tell you how I do it, in case you're interested. Or even if you're not!