It was per camera and they offer different packages. The one I used was the base option with 1000 pictures per month and 10 videos. once you set up the account and have the app you can set up a shared drive for anyone you want to check cameras. The only cost was through Moultrie 1 camera was $9/mth and all three equaled $30/mth. This can go up based on the needs of images.
These are great, inexpensive cameras. They don't have the highest quality photo out there but for the price, I think they're damn good. I've had mine out in the elements for two years and still works as it should.