Outside freezer- Is it worth the money?

We moved into this house last summer, and brought our old refrigerator with us to keep in the garage. I have enjoyed being able to buy foods in bulk, and double meals when I cook and store them in the freezer for nights when I am too tired to cook ( which came in especially handy when Avalyn arrived).

Lately though I have been wondering if it is costing more in electricity than it is saving us? Our last electric bill was $274, and I think part of that cost is from trying to keep the fridge and freezer cold when it is 100 degrees in the garage.

It is about halfway empty at this point - should we try to eat everything out of it and then shut it off until the weather cools down? Or is the cost of running it nominal? I'd love to hear from anyone who keeps an outdoor freezer.