Roger Federer is massively overpriced for a tournament he has won before, although Clay isn't his favourite surface he does have a decent record here.
In 2011 he got to the final, losing to Rafael Nadal in 4 sets after beating Djokovic in the Semi Finals.
In 2010 he got beat by runner up Robin Soderling in the quarter finals.
In 2009 he won the title, beating Robin Soderling in straight sets.
In 2008, 2007 & 2006 he lost in the final to Rafael Nadal, he is likely to be in the same side of the draw as Nadal as they will probably be seeded 2 & 3 but he cannot be ignored at such a price and must be backed