Melzer is fresh, hasn't played since wimbledon and will be playing in his home country of Austria. Andujar just won a final a day ago, not sure he's ready to kick it back into gear and make another run.
Melzers last 4 losses on clay have been to top players such as Tsonga, Murray, Monaco and Vesely(up and coming young gun). I just think the motivaton will be there for Melzer behind the home crowd against a fatigued Andujar still hungover from his finals victory. The + money is definitely worth a shot for me.