Alice, you have most likely SOLD your Littleton home, by now, since this question was asked in 2010.
The market has changed dramatically since 2010. Today, April 30th of 2015 we are in a Seller's Market. There is a shortage in our current inventory and buyer demand is at an all time high! In today's market, upgrades are usually unnecessary to sell. However, if you'd like to get the most $$$ for your home, some upgrades may help you. These upgrades need to purposeful and appeal to a wide range of buyers. As far as a credit goes, I would not suggest a credit for anything in this market. Just lower the price and buyers will be all over it!