Are you referring to high or low bush blueberries? Unfortunately the price of blueberries has fallen drastically for the good sweet low bush you get out of Maine and New Brunswick. It seems most stores now only carry the not so sweet big ones and I believe the market has been flooded thus the price is a lot lower now. I looked into a property in New Brunswick that had 16 acres of them (low bush) plus other acreage and really considered it heavily (to move down there and live/work on the property) but unfortunately the information I found was not good for reselling just the berries. I don't recall the price per acre though as this was earlier this year.
Now if you can take blueberries and make a side product with them and niche, then you'll do okay. I thought about that as well but because of my other business, timing is just not right for me.