yes you can reload for shotgun, but it's not worth the time or the effort i find personally, however with the .223 the .243, and the .308 you can reload,
my advice is get yourself to someone beside you to show you the in's and out's, the .243 and .308 are relatively easy to reload for, as they are not as picky about bullet powder combinations as some calibres.
how expensive depends on how much you want to put into it..........
main criteria are a good set of scales, good set of dies and patience, you can start off relatively cheap, and trade up as you go, is it worth it hell yeah....
you