Only time will tell. I really think in the next year or two, Hulk 1 will go up significantly . and 4K+ for a 2.0 will be common.
Do I think that this is the future of the book? Yes I agree 100% but I think that this price tag is a few years away. Closer to 2014/2015 as you mentioned above. The movie is slated for 2015 and I agree the book is important. You guys know me and you know I love the Hulk. I offered 4600$ on the 4.0 on eBay. Was countered with 4750$ and have been debating it. I was about to pull the trigger last night after I completed a huge sale. But my buyer ended up buying a few thousand dollars less than I expected, so right now I am waiting for Chicago to roll around.
Does this book have great upward potential? Yes should people invest in it now? Yes with out a doubt. Is a 2.0 worth 4200$? No, not while there are 4.0s to be had for just a couple hundred dollars more.