Last year I searched in Lakewood for an esrog. I found that nice esrog costs much more In Lakewood than in queens. I'm assuming thats because of supply and demand. Since there is much more of a percentage of people in Lakewood who want a nicr esrog, and only a small amount of people willing to get a shvach one, the sellers can and have to make more money off the nice ones to pay for the bad ones they cant sell.
