Why would you want to do low carb anyways?? Are your motivations for weight loss, or do you just consume way too much of them?
I think when people limit themselves immediately, they're bound to fail and rebound to old habits. Your physical body goes from one routine to a drastically different one, and with eating, this tends to fail all the time.
You could start by switching to whole grains (examples: whole grain bread instead of white or bagels, and whole grain pastas) and brown rice, and cut back on sweets. (For example, instead of ice cream, we did shaved ice and put fruit toppings on top). Substitutions are easy, and not expensive, and they give your body some time to adjust to changes as well. I definitely agree with the oatmeal and brown rice bit -- barley as well, these are all great ways to go good-carb that your body needs and likes without sacrificing the 'feel full quickly' convenience. Beans are cheap and convenient - just throw them in a 2-to-1 ratio of water in a crock pot and add whatever meats you want.
Eggs are really cheap and versatile. They're easy to cook, and awesome, and can be flavored in a million different ways. Lean meats are not so expensive if you shop smart, and marinades keep the flavors changing and spiced up.
Finally, I suggest a big up-take of veggies. I don't care how you need to eat them (whether raw, like me, or puree'd to create a vegetable-y liquid to stick in spaghetti, etc.) but veggies are a key factor in reducing the carbs normally consumed.