I've seen that some objects have a higher value then others, but has anyone actually tested this and worked out what's more valuable and by how much?.
These are rough values I've found. Now that I know we'll not see another wipe I plan to do some more testing.
Belt clusters - 0cr
Rings, Resource Extraction Sites - 0cr
Stations - 0cr
Iceballs, Rocky, Rocky/Ice ~ 500cr (varies a bit, but don't expect much)
T-Tauris ~ 1000cr (ish)
Most gas giants (Class 1, Class 3, Class 4, gas giants with life) ~ 1000 - 1500cr
Most stars ~ 1500cr
High metal content planets ~ 2500cr
Ammonia worlds - ?
Helium-rich gas giants - ?
Wolf-Rayet stars, Herbig Ae/Be stars - ?
Metal rich planets ~ 5000cr
Class 2 gas giants ~ 5000cr (I don't know why these are more valuable)
White dwarfs, Black holes, Neutron Stars, Earth-like planets ~ 10000cr or more.
As far as I can tell you get a "base" value for scanning a particular type of object, plus an additional amount depending on the object type and its mass, with severe diminishing returns. So a 1 Earth mass high metal content world will get you a certain amount, and a 10 Earth mass high metal content world will get you a bit more, but nothing like 10 times more.
I don't think the precise metal content (etc.) of a world matters, although there appear to be subdivisions among some types of world (e.g. some ice worlds might have 10% metal, but tiny little ice moons tend to have only 1% metal), and there are variations from system to system.
I think scanning distance is determined by object type and radius; I was able to scan some (relatively) low mass supergiant star from over 50,000 light seconds distance.