Ick. I hate sweetcorn. It can be anywhere from 50c to $1 (Australian), depending on the time of year. I don't care as long as I don't have to eat it. I get it for the rest if the family on the strict condition that I don't get served it.
I don't know about the supermarkets, but the local produce market that I buy from charges $.50/ear for organic corn. Well, I guess everything they grow is organic. It is a Mennonite farm community's produce stand. I haven't had tomatoes like the ones I've bought from them since I was a kid. Delicious, juicy, tender skin. I have not bought any corn from them.