I thought we've talked about this before, but couldn't find it when I searched. Maybe others have a better idea where to look and will post the links to the other discussions.
I understand working within a tight budget. I'll give you what worked for my parents who are retired and living on a very limited budget. First thing is don't try to follow the suggested menus in the book. Look at them to get an idea, but create your own.
Print out the foods to enjoy list. Grab the local store sales ads. Find out what's on sale that's on the foods to enjoy list and make your weekly menus from that list. It doesn't have to be a detailed menu, just a rough idea.
The first 2 weeks were the most expensive time for me, I was getting used to the idea, wound up buying way too much fresh produce. After I got the hang of it, the costs went down. Don't go crazy buying all the foods to enjoy at the same time.
The whole idea is to adapt South Beach to your way of eating. I would never buy shrimp just because my diet said so. I only buy shrimp and scallops when it is a price I like, same for fish. I only buy fish at $2.99-$3.99 a pound. I live close to an Asian market so there are usually several types of fish at that price. Try to follow the basics of the book, stay as natural as possible-yes I know that fat free half and half is not found in nature, keep away from the processed foods-white bread and white sugar.
Beans are great! Beans are your friend! They are filling, cheap, high in fiber, taste good and are great on a budget. After dried beans are cooked, they freeze really well so you don't have to spend all your time waiting for them to get done.
When pork loin and skinless, boneless chicken breast is on sale, I buy several pounds, slice it/separate it into 1 pound packages, wrap it well and place it in freezer bags and throw them in the freezer.
Same with cheeses-Kraft slices fat free or 2%-I only buy when they are $2.50 or less a pack, then stock up. They last a long time. When the shredded cheeses go on sale, I stock up on those also, just throw them in the freezer and remove them the night before I need them. Just make sure to allow it time to thaw in the fridge. Don't thaw it on the counter top to thaw, it clumps into a mess.
Shop around different markets in your area, if you live in a large city you may be able to find an asian market that has great prices on produce and tofu. If it's a large city. Some areas have food co-ops where you can get good prices on bulk foods. If you live in an area that has a Trader Joe's. TJ has good prices on the more "fancy" items.
http://www.traderjoes.com/locations/index.asp
If you live in an area that has an Aldi's-they have good prices on basic items.
http://www.aldifoods.com/
Laughing cow cheese is very expensive. It's convenient, but not crucial to this way of eating. Pre-packaged mozzerella cheese sticks are nice, but you can buy a block of part skim milk mozzerella and slice it into sticks yourself and place them in baggies for snacks. Same goes for yogurt, buy the larger container because most of the time it's a better value, then divide it into 1 cup containers. This way you can also experiment with different flavors.
The sugar free syrups are nice but expensive. If you can swing it, it might be nice to have a bottle of one but again it's not critical. You can kind of get the same effect with extracts from the spice section in the grocery store and packets of sweetener.
Prepared Jello cups are convenient, but you can buy the 1/2 cup containers and make your own jello cups for a whole lot less money.
Those popular riccotta cream desserts-well, riccotta cheese can get really expensive. Wait until it goes on sale. I've read that some people have frozen them, I never got around to it and it always went bad before I finished a carton.
I may be flogged and run out of the forum for saying this but:
When you are on a severely restricted budget, go ahead and buy the cheaper cuts of chicken. I can buy a 10 pound bag of chicken leg quarters for $2.50 on sale I know it's not SBD friendly, but when you are on a tight budget it's still healthy food. Just remove the skin and fat before cooking and maybe don't eat as much as you would a chicken breast and eat more veggies.
My parents, on the fixed income, nearly had a stroke when I told them to buy chicken breasts and pork loin. Mom refused to spend that type of money of food. And they still lost weight on SBD. (Until the cry of the ice cream in the freezer became too much and they fell off the SBD wagon never to return because the cookies and leftover chocolate easter bunnies-parents freeze everything- also attacked them and they decided that at 80, the cookies and ice cream were going to win and set back to enjoy themselves.)