Bridgestone bicycles of a certain era are generally considered to be quality products, although Bridgestone no longer makes bicycles for the US market. Ask about the condition of the tires and tubes, are the wheels true, when the last tune up was, are there any severe dents in the frame, the condition of the brake pads. Ask what the frame size is, bottom bracket to seat post; alternatively ask about the height of the last owner to guage whether it is appropriately sized for you.
Finally, ask if the seller could meet you with the bike in a public place so you can take a test ride. If you like it, you can ride it home.
Stadard barganing rules apply.