I have a old Univega rover that I got new in the early 90's Its is still a solid bike, and has been thru alot. I have done a few upgrades to keep it current and use it as a bike path bike to follow my kids on. The Derailure is most likely a cable adjustment. I would look on some of the closeout places, CL or ebay and get 8 speed stuff for next to nothing. ( I believe that bike is 8 speed ). I would say 30 is a great deal if the frame is solid.
Congrats!