Brown sugar doesn't last nearly as long as regular sugar in your food storage. If kept in its original bag, it will turn hard in a relatively short amount of time. You can buy brown sugar (C&H Brand- the good stuff) at Costco or Sam's for about $13 for a 25 pound bag. That makes it about 1/2 the cost of buying it at the grocery store. Here is a way to store brown sugar that will keep it as fresh as the day you bought it. What you will need, however, is a FoodSaver, and a mason jar attachment.
I purchase a 25 pound bag at a time of Brown Sugar from either Costco or Sam's.
My kids like to help put the brown sugar into jars. I pack it in tightly using a wooden tart press (you could use anything that fits down into the jar). Each quart jar holds about 2 pounds of brown sugar.
When the jar is full, wipe off the rim, so no sugar is on it. If there is sugar on the rim, the jar will not seal.
Put the lid on the jar (you do not need to do anything to the lid), and then put the jar attachment (seen here- can purchase on amazon.com, or get a a kitchen specialty store) over the whole top of the jar.
Plug into the FoodSaver and seal! The food saver extracts all of the oxygen out of the jar and seals the lid. When you open the jar when you are ready to use it, the brown sugar is as soft as the day you sealed it.
The finished product ready to go into my food storage room.