Cheaper than Salad bags...

I used to buy the bags of salad from Dole or whomever that came with dressing. It was a seemingly cheap way to get my greens with a meal. Here's what I've discovered since then: Dressing is the easiest thing in the world to do on your own.
For $2.49 you can get a bag of salad at Rainbow Foods that'll feed three to four people for one meal. For under $5.00 you can get a head of green lettuce or a bundle of spinach and the makings of your own dressing that will feed four people for at least four dinners.
My favorites:
Vinaigrette...
4 parts oil (Extra Virgin Olive, Grapeseed, Etc.) ---(If bacon is used in the main course I have been known to use the bacon fat as the oil in the dressing)
1 part vinegar (balsamic if using spinach, cider if serving with pork, rice if soy is involved in any way, red wine under any circumstance whatsoever)
a pinch of seasoning (basil, rosemary or garlic for balsamic, garlic or fresh ginger for rice or especially cider, just about anything green for red wine)
green onions, if you have them, or fresh chives, etc.
For creamier dressings (ranch, and such)...
1 cup each mayo and buttermilk with a teaspoon each of parsley, pepper, salt, and garlic, and add a pinch of dried onion.
This, combined with the super cheap greens from the produce department, is the easiest salad you could ever come up with. No matter what meat or pasta you do at home, a salad is so easy, it's a sin to pay for a corporation to put it into a bag for you.