Please follow the below link. It will show you price's for many brands. http://www.netdummy.net/CDROM.asp
they range from about $200 to $700 :) i little expensive but they are really nice
It cost £20.00 to sit on Henman Hill, if you arrive after 5pm cost is £14.00.
It can cost 30-40$. More or less depending on the quality.