I'm sure glad I added these items to my collection years ago... not so sure the Armstrong would be within reach now! The "Apollo 11" inscription is quite uncommon and adds a great deal of value to this undoubtedly authentic exemplar. Further, the signature is nicely preserved and exhibits very little fading so commonly seen in Armstrong signatures. My theory is that Armstrong used a blue Flair marker... a pen notorious for fading. Plus, so many people probably displayed their signed photos in a frame -- another reason a high percentage of Armstrong signed photos are badly faded. I purchased this from the original recipient, Scottie Hensley, about 7 - 8 years ago.
Even though Buzz Aldrin is a common signature, his signing fee is high (around $400 last time I checked). Apparently, he still gets people to pay the fee. A common signed Aldrin item might command $100 - $150 on ebay.
Mike Collins used to be the most uncommon signature among the Apollo 11 crew. He signed freely for a few years after Apollo 11 until the mid-70s when he worked at the Smithsonian. After that, he became more reclusive; he didn't hide his dislike for autograph requests. In recent years, he has conducted private signings and appeared at a few signing events. Still, his signature is in high demand.
A signed Apollo 11 crew photo is one of the holy grails of astronaut autograph collecting, commanding thousands of dollars. While I'd love to have one in my collection, I think there is a higher probability of me being the next man to walk on the moon!