I didn't see anything there saying he was trying to negotiate with Marvel. Is there another link to him saying that?
It would also be tricky to what the guy actually owns. He created the initial design, but didn't come up with the name, the back story, the personality, etc. Everything but the name and design are probably owned by Marvel. Does anyone know differently?
I think Marvel would certainly be willing to outright buy the character, but I doubt they would be willing to do anything else. The character is useless to take to another publisher.
If the guy was smart, he would sell the character to Marvel. Maybe ask for a percentage of the profits.