Kate, you can estimate the value of this (some remodels may not be accurate so read the disclaimer) from http://www.remodeling.hw.net/facts-and-figures/cost-vs.-valu
the next report comes out in December. Downloads are free but they ask for an email address. I did not receive any spam from them afterwards this spring.
A local real estate professional can help you make a decision based upon what's happening in your immediate subdivision. See what's selling before making a decision. Trulia will also have recent sale activity. Some will be sheriff auctions and might not be accurate.