As above what they worth?

 

Also I'm thinking of putting a set of rs cams on my st do I need rs valves/springs ect or just fit straight onto st block? Any advice please.

 

not a great deal, 50-100 quid maybe. They'll fit straight in.
The inlet cam is the same, exhaust has a slightly different duration. Most people don't bother with them as they don't really offer a great deal of perfomance gains