Hulk 181 according to the above,is not exactly a rarity.It's demand is based mostly on Wolverines 1st full appearance than anything else.There will be copies of this book in high grade available for many years to come.Don't forget about other factors too such as hoarding,undiscovered collections,lost warehouse etc.
Don't get me wrong though-this book is baby steps in terms of it's ultimate spec value and investment potential.But there are still other treasures out there that can be had for far less in the same condition that will always have an"up" curve and/or are on the rise.Some of them may even surprise the living daylights out of you.