That book has been off-and-on hot for a long while now. Even raw copies have ranged from $4-$8 for quite a while even when the market was slow.
1) Part of the 3-part story where the original X-Men form X-Factor.
2) Return of Jean Grey after the events of the Phoenix where she supposedly died.
Cap explains to Mr. Fantastic about the strange object they recovered from the bottom of Jamaica Bay earlier that day and how it has a living creature inside. When Reed decides to check it out for himself, he places a hand on it but some force attacks him and throws him back. Reed's fall is cushioned by a forcefield projected by the Invisible Woman. On Reed's direction, Sue uses her powers to make the capsule turn invisible, revealing the unconscious body of Jean Grey inside. However, due to the brevity of their glimpse of the woman inside the capsule, nobody present can identify her. After discussing who the woman could be, the Human Torch and She-Hulk decide to go and reunite with their loved ones leaving Reed and Captain America to try and solve the mystery.
Things being to get strange when suddenly objects begin levitating all over the Mansion, waking Sue from her sleep and startling a fatigued Reed Richards and Captain America after they have spent eight hours working on trying to open the capsule. To their surprise, the woman inside the capsule finally breaks free. Jean, still thinking that she is a prisoner of Stephen Lang and his X-Sentinels believes that Reed, Sue, Cap and Hercules are more Sentinel constructs of heroes and attempts to attack them. When Sue restrains Jean with a forcefield, both Cap and Reed realize that who she is, and that as Marvel Girl she was a member of the X-Men who has been missing for many months. Telling Sue to lower her forcefield, Reed asks the confused Marvel Girl to explain what happened to her.
OIC.
So is that Sue Reed with a mullet!