Are you JUST going to be submitting a disavow file? Or will you also be filing a reconsideration request?
I would keep a copy of his reply where he was asking for money in return for removing the link. I would put that in a google docs file and reference in your reconsideration request.
"Don't get into confrontations when you don't need to."
If you make threats that imply his site will be blacklisted because you put it in your disavow file, then he will - knowing that you are afraid of spammy link - find the spammiest links in the world and point them at your site. He's probably got lots of directories and lots of cheap spamming tools.