Rick Hahn ASST GM has a podcast with Rongey on how actual teams value other teams farm systems differently than Baseball America or any other publication.
As far as what they have to give up? :dunno: Depends on the pitcher, how much or less of salary get eaten ETC. Im sure there is a deal out there when more pretenders become sellers. If we are talking Ryan Dempster who I want but I doubt comes here because of more desperate teams who have real big holes in the rotation....clev,DET etc....I dont think he nets something that the sox dont have. Im sure if KW really wanted demp he could get him. FA to be, on the DL etc.....but im sure there will be a team that will give up more to get a starter out of desperation.
so basically it all comes down to who, contract status etc etc etc. if he wants a 2 or 3 he could get one.