Based on what you say, does not like you read magazines or color books. If majority of books you like and read are novels or pure text books, you should return the Nook Color and won't miss it. The Kindle 3 is less expensive and will do exactly the same: let you read a novel. Kindle is also lighter and easier to use for long reading sessions. As long as you have proper light, it works awesome.
For a better price, you can check on ebay or even used Kindles at Amazon. Lot of people find that such devices are not what they were expecting so you can find good deals easily!