I would make sure you know the product and how well it works, some of those good buys are not so good if you can't use it.
I bought some off the net and threw away 3 bottles of the crap. Check out tower if your looking for a larger quanity, so far I have had good luck with it with the exception the med is a little on the thin side.

As a rule I don't let mine set around long enough for it to go bad, but the fridge is the best idea from what I have seen and read, Make sure you seal it up good also.