The deal does include $1 million in incentives, and not entirely out of reach incentives, which coulld bring the entire take to $8.1 for AD should he reach them. But the raw numbers are $7.1 over 3.
The Skins would have paid him $11.2 million over the first three years of his old deal, so in camparison to that the Bears got a bargain and AD clearly left a big chunk on the table just to get out of dodge.
Then again, to flip the script, the Redskins gave him $5.6 million for one season - about the going rate for a quality safety in free agency (although obviously way too much for any team's "personal protector") - while the Bears will pay him an average of $2.4 million a season, less than half of that.
At this point, barring his physical, he is ours, so I really don't care what money he is making as long as he does his part.