Draft and Trade Talk Message Board
I think most FA managers will recognize Beachy as the more valuable pitcher, his .047 ERA and penchant for break-out potential by most pundits will have him held in high regard. It is with that said Matt Garza is the better player. Consistancy is the gold seal of success in Fantasy Baseball and Garza has averaged 190+ IP and over 8/K9 the last four seasons.
That covers the relative value of the two pitchers you are offering.
As for trading for Bourn good luck. Two problems exist: a) he has been incredibly hot lately, and has got his avg up to an astoundng .338. b) most players who drafted him did so with the expectation he would buoy their SB standing alone - something he probably will do. Medocre pitching is so plentiful in the standard league format, it would be fairly impossible to get him for a pitcher outside of the top 15.
Perhaps, and only if, your competitor has zero pitching and has both Emilo and Dee Gordon could you get Bourn for Garza or Beachy.
You will be better off looking to the waiver wire for cheap steals - De Aza, Scheter, etc.