I don't believe it will hurt them that much at all. Relate it to revenue, during 2009 the Yankees had $375 million in revenue, which means that for every dollar the Yankees spent on salary, they had $1.86 in revenue, about the league average.
At the end of his career its entirely possible he'll be the all time home run's leader and first player to join the 800 club. Its unfortunate his career will forever be tainted by being linked to steroids.