According to WNSP (Mobile) Saints Going After Mike Wallace

Wallace would be great as a Saint, but it would be more of a luxury than a necessity. He would be very nice to have, but 10 or 11 million a year could be much better used on the defensive side of the ball IMO. Same goes with a first round rick, Patterson or Austin would be nice, but there are many defensive players that would be more impactful on this team.