An Actual Grocery Budget

i hate to admit this, since M and i attended Financial Peace University two years ago, and since i'm such a math nerd, but we've never set a grocery/household items budget. at first, i figured whatever we spent was well within our means, and then once i started couponing almost a year and a half ago, i figured we were spending even less. so all was good, right? well, in a way, it was. each month of 2009 i tracked on a spreadsheet our grocery and household expenses. we were well below the $400 average we spent per month pre-FPU and couponing. this year, however, i decided to set a budget and stick to it. i reviewed average monthly expenditures for 2009, factored in inflation, countered by the fact that our freezers and pantries overflow, and decided to go big (small?!?) by setting out budget at $100 per month.

this month we've been participating in the Eat From the Pantry Challenge, so we haven't been shopping that much. there were some freebie deals i just couldn't pass up on, and milk and produce were allowed on the challenge. so far this month, we've spent just under $50, over half of which went to two large boxes of cat litter (which should last through the end of february or so) and a ginormous bag of kitty kibble, which will last through february as well.

so here's my dilemma: i still have $50 in the budget, and 5 days left in the month. we won't actually need anything this week. but . . . kroger is having a megasale starting tomorrow, and kraft cheese is at a stock-up price. admittedly we still have a fair amount of cheese in the freezer from the last stock up sale, but there are certain kinds we're out of that i'd like to have on hand. the sale should run two weeks, though that's not guaranteed, but it definitely runs through february 2. so, i can't decide if i should go ahead and hit the sale this week, or if i should wait until next monday and shift the expenses to next month's budget.