Believe it or not, top-shelf bacon. It's got more bacon in it. Less water. You're not paying nearly as much more per ounce of actual meat as it looks at first.
Lots of "organic" produce has a significantly longer shelf life than the basic stuff too. Never mind whether it's any healthier or tastier, I'm not saving any money if I pay a dollar less and it starts molding before I can eat half of it.
If you really want to step up your game, try buying raw meat, cooking it, and slicing it for sandwiches. I do this with chicken and it's served me really well at very low cost.