Well I had a road bike for awhile before I understood it's value as well. I all I have to say about it's value is that, it will cost a bit to pick up a bike as functional as that bridgestone. You won't be able to sell it for as much as it is worth. I hope that makes since. In other words it's monitary worth is not near as much as it's functional use, worth.
One good way to find out how much you can sell it for is to, make a craigslist add and don't put a prices just ask for offers. It will give you a range of how much people are willing to pay for it in your area.