I think they're at Costco when Costco has them in stock. I just bought some but can't remember for sure how much they were. It was a pretty good size bag - maybe 20 or so, and I know it was less than $20. They are not knotted, though. They're long and straight - maybe 10" or so.
One of my dogs loves em, but the other one will only chew one if she's able to steal it from the other.