Misty,
You don’t have to spend any money at all on this. Go to http://www.biblegateway.com/resources/audio/ and pick your translation and listen for free. There are 6 English translations, including the NAS, to choose from for audio listening.
Bible Gateway is also a great site to compare translations when you’re unsure of the meaning of a passage. For reading purposes, I believe their translation list is exhaustive.
Now, if you’re ever interested in dramatized versions of Bible stories for your kids to listen to, I recommend the Your Story Hour series. You can find these many places online, including eBay. My kids listen to these at bedtime or quiet time or in the car, etc.
Blessings,
Christie