Cheese lasts a long time in the fridge, and even iceberg lettuce does as well. My local burger/micro-brewery has been sliding in quality for the last two years and I finally reached my tipping point. Normally, it's about $12 for a 1/3lb burger and fries there.

So I found a local butcher who makes a 'steakhouse' grind (chuck, brisket, short ribs) for about $7/lb. Two slices of cheddar are about a buck for non-Kraft cheese, buns and condiments are about another buck. Takes me about 9 minutes to cook at home, and I have a custom, super fresh and hot burger that tastes better than anything I've every had at a restaurant. Now I do miss out on fries, but eh, chips will do as a replacement. At the end of the day, I have a burger and chips for about $5, plus leftover stuff for other sandwiches. Throw in a decent beer, and I'm still cheaper than the microbrewery. And no driving required.

Of course, I have to do the difficult part of cooking. /s