Why would you stay out of a maniac's way? He's trying to give his money away. Don't run from him. Outplay him and take his money.
You're trying to count outs and pot odds. You are forgetting that there is a very good chance that your ace-high is good, and that he has just one low spade or nothing at all.
Given the actual hand, you had a
coin-toss, and could call even if it were $600 more.