It turns out this gentleman is Will Ryan, who in addition to being a great guy/composer/lyricist/and voice actor for tons of wonderful animated films, also bought the first copy of the first issue of American Splendor, depicted here in the Harvey Pekar story illustrated by Gary & Laura Dumm which comes with the DVD of the film:
And I was pretty happy about that! Here's the link to Will's cool site.
...As far as Denis goes, the left hand doesn't know what the right is doing. He may have already fled to Mexico, and is living on the rich spoils of our comic whilst I toil away in obscurity. Thanks a lot Denis, you bastard. I'm keeping the $2.50.