Looks like Marvel Knights Spiderman #20 became more desirable as the announcement has come out that Mary Jane Watson will be joining the cast of Invincible Iron Man with issue #4.
Comic Book.com had the story:
Mary Jane Watson is leaving the web-head behind, and joining Tony Stark’s supporting cast as of December’s Invincible Iron Man #4.
Marvel made the announcement today. Mary Jane is said to play “an unexpected new role” in Tony Stark’s life.
“We were at one of our glorious Marvel publishing retreats and certain characters got brought up, sometimes almost accidentally, and I found out that nobody had anything going on with Mary Jane,” writer Brian Michael Bendis tells Marvel.com. “I sat with that for a while and I always go to this place in my head where I [wonder] what the most interesting thing I would like to see that character do now and it fell right into the ideas I was already cooking for Tony Stark.”