Fantasy Baseball Trade?

Hey guys, I've played Yahoo! Fantasy Baseball for years, but I'd like to hear some feedback on this trade I'm proposing. I'm giving up Michael Young, Matt Holliday, Curtis Granderson, and Placido Polanco for Cliff Lee and Carl Crawford. Yes, I know that Crawford's on the DL and was in a bit of a slump, but I'm looking into the future (playoffs) instead of the present.