Rick Dee's Top 40 can cost up to forty dollars. The cheapest you will find it will be on Ebay or Amazon. You can also buy the MP3's from Amazon which is cheaper.
It started in September 1983 with KIIS-PM (Clear Channel Communications.) It was then moved to KIQQ, or known now as KSWD. From there it moved to ABC Radio Networks,and was owned by Dial Global...
You haven't specified the country. In the US, the weekly radio countdown called "American Top 40" started in 1970. However, Billboard Magazine was tabulating song/music charts back in the 1930s.