There has been a number of threads here about this subject, just do a search for "budget cooking" or stuff like that.
But, what kind of budget are we talking? $50/week? $150/month? Everyone's definition of "cheap" is different :)
Also, one of my favorite blogs is budgetbytes.blogspot.com/
Everything I've made from there has been really delicious, and while she doesn't provide nutritional info, I end up building the recipes in the recipe builder and most of them end up fitting right in with my eating plan, even when I eat bigger portions than she calls for.... like she'll say something makes 6 servings and I'll make it as 4. That sort of thing.