I'm part of a 16-team league with a 40-man MLB roster, and a VERY deep minor league system (65 roster spots).  I've owned the team for 2 years; when I got it, it was a middling veteran club with a very weak minor league system.  I've been on the youth movement for the past 18 months, and have acquired and/or developed some good young players.  The problem is, my minor league roster is stronger but needs some depth. 

One of my young guns is Cahill, and I've been offered a pretty penny for him - 2 top-15 picks (we have two drafts each season - one offseason, and one midseason) and two prospects (I'll likely choose Danny Duffy & Jean Segura).  Other SPs that I have are Volquez, Holland, Cecil, and newly re-claimed James McDonald, so there is some talent there, but it;s not overwhelming. 

I'm wondering if I should capitalize on Cahill's big season, which he likely won't ever repeat (extremely low BABIP, still below-average K/9 rate), to help build my farm system.  The best SP prospects that I currently have are Garrett Richards and Randall Delgado, so Duffy would give me a bump a little closer to the majors.

Thanks in advance!