One thing important to note about cranberry juice is to buy pure cranberry juice. If you buy cranberry "drink" or "cranberry juice blend" there is likely to be very little actual cranberry juice in it.
What you will find with anything other than pure cranberry juice is that it contains lots of sugar and probably juices like apple, which are much cheaper to produce.
I pay about $5.99 for a one-quart bottle of cranberry juice. Check the label and make sure there are no additives in it before buying.
If pure cranberry juice is a little too strong for you, you can dilute it with water yourself.
Cranberry is also very good for the immune system in general, which many need this time of year with colds and flu around.