I have a copy of Amazing Fantasy 15 that I bought about 35 years ago. It is still in okay shape (around a 4-5 grade) and have the opportunity to get Stan Lee to Autograph it for $350.00 bucks, as well as meet the man and get photo op. I've met Stan before (almost 40 years ago, which started a lifelong love of Marvel) and doubt the meet n great would do anything more for me. But as an investment, is it worth getting my most valued comic signed? Thanks for your input.