I've purchased 14 different Apple products over the years and I've never purchased AppleCare for any of them. I've never purchased an extended warranty for anything, really. I don't believe in extended warranties. It's like fast food companies charging you an extra 50% for fries and soda that aren't even worth a fraction of the rest of the meal.
There's only been one time I've had to pay out of pocket for repairs, and that was a $70 bill to fix the power supply in my 24" ACD. Thing is, I bought that thing used, so I shouldn't even count it... Am I lucky or just careful? You decide.
So if I were you, I'd do the 4S without AC.