If it is a villain you will never see again (on big poker sites) a fold is not too wrong.

But if this is someone you will encounter again and again I will rarely give up that much equity for a small bet. I want to instill fear in people and make them believe they have no fold equity- especially not with small bets. Your big preflop raise often means an overpair. Represent one- then you know you are beat if he still calls.

More important than your decisions are the implications of your decisions. Against regulars the metagame aspect sometimes becomes more important than the actual hand in play.