You should see what tourists will pay for certified organic wild Maine blueberries. The only difference between them is they come from a field that wasn't sprayed.

They pay three times the price and six times the wholesale price. They are the same berries, harvested the exact same way.

You can double the price again, if you have someone hand pick them instead of raking them. Even better, you can charge them about the same price and let them pick the berries themselves.