Bronze Age Comics (1971 - 1983)

Incredible Hulk #181

1st Appearance of Wolverine. This book is relatively common, but don't let that fool you. The high demand for this book has made it a very expensive item. This comic can fetch anywhere from $1k to $25k depending on condition. 

Giant Size X-Men #1

1st Appearance of many new members of the X-Men and the beginning of a new era for the team. This book falls under the same category as Hulk #181. It is not necessarily rare, but it's high demand has made it a valuable book. It can sell from anywhere between $1k to $25k depending on condition.