I generally find the trend of blogging about your meals rather droll, but I was struggling for a bit about what to do for quick cheap paleo lunches during the work day, so I'm going to start recording some of the solutions I've found.
Here's some generic tips:
Tip#1 Eat at a grocery store.
I have two grocery store choices for lunch, one grocery store is within walking distance of work, the other is further away, but fancier and has a food bar and sit-down dining space. Grocery stores generally have a plentiful supply of things you can eat, it's just a matter of how to select reasonable portions and assemble them quickly without a lot of tools.
Tip#2 Have minimal prep materials handy.
I carry in my purse a pocket knife for cutting into packages and ingredients that were not sold as convenience foods. At the food bar place I can get an empty food container, plastic spoons, salt packets, and other little touches. In my cube at work I have a small cutting board, a table setting, some salt, oregano, and olive oil.
Tip#3 Eat at an unusual time.
If you want 1/4 lb of quality cheese, you may have to go to the deli counter, and that may be a bit of a time hog at rush hour.
Tip#4 Spend like you're eating out, not like you're grocery shopping.
You might shy away from $8/lb foods for making dinner, but if you're spending $8 on a fast food meal, you can surely spend $4 on a half a pound of quality ingredients for lunch. Your budget may limit variety, but don't let your budget steer you into buying stereotypical lunch foods.
Tip#5 Drink some of your calories.
Most stores have single serve bottles of Vitamin D milk and juice. Personally juice has too much sugar for me, but a bit of milk polishes off small meals nicely. Even if you're stuck at a fast food restaurant, milk is often on the menu.
Obviously you can do lunch better and cheaper if you just make your lunch at home, but sometimes it is more convenient or social to go out for lunch, and it's nice to have some options when that comes up.