Developing the Domain will increase the value (building a website), this alone should have increased the value a bit (I'd say the average goodlooking homemade and customized design - mid $xx) afer this you'll need to start building traffic to this website and start making revenue and then you'll have a real valuable online real estate for which you'll easily find buyers in places like Flippa or even in the forums but at that point you might enjoy the passive revenue so much that you no longer want to sell it :D...
Sounds easy is not...
If you don't know much about programming and or webdesign then Noomle is a great free alternative: Noomle Domain Name Parking and Minisites Forums


