How accurate do you find those websites that give a value? They might be good at measuring stats from an MFA perspective but they can't possibly be looking at the domain and making the creative decisions about how the name could be used. I probably wouldn't give it a huge price because of the .net but up1 is awesome if you are selling traffic, doing social media promotion or even career counselling. It might be a matter of holding onto it until the right buyer comes along rather than selling quickly. If you want to develop the site with an actual business then you'll boost the value.