The simplest is to imagine that a moment from now, Omega walks up to you and says "I'm sorry, I would have given you $10000, except I simulated what would happen if I asked you for $100 and you refused". In that case, you would certainly wish you had been the sort of person to give up the $100.

I liked this position -- insightful, so I'm definitely upvoting.

But I'm not altogether convinced it's a completely compelling argument. With the amounts reversed, Omega could have walked up to you and said "I would have given you $100 except if I asked you for $10.000 you would have refused." You'd then certainly wish to have been the sort of person to counterfactually have given up the $10000, because in the real world it'd mean you'd get $100, even though you'd certainly REJECT that bet if you had a choice for it in advance.