I've never used store bought brines, but at $7-$8 a pop, I'm sure you can make a much better brine from one of the recipes here or elsewhere for less.
Use your imagination when it comes to brines, the only rule is a brine should have 1/4 cup of salt per quart of water. Any less you're simply soaking the meat in salty water, not brining. After that let your imagination/taste be your guide as to what other flavors you want to add.
I also like to add 1/4 cup of sugar (white or brown) to my pork and poultry brines.