Muahahaha. I just got back from the lego store. Guess what color I am building in?
So, I had read that you can buy the cases that they have in the back. You have to ask the employee's there. I would imagine a lazy employee wouldn't want to be bothered. I'm tired of filling those Pick a brick cups and I don't have the time or patience to stick every brick together then pull them apart later to save a few cents. I'm building primarily in one color so I'm looking to buy in bulk to save $.
Here are the boxes weighed for curiosity... I purchased tan 1x2, tan 2x4 & tan 2x6 cases for the large scale castle I am working on...
1x2 case 5 pounds, 4.2 ounces
2 x 4 case 3 pounds, 8.6 ounces
2 x 6 case 3 pounds, 5.1 ounces
So I opened the 1x2 case. There is no packaging inside, just loose bricks...
Now a large pick-a-brick cup will hold roughly 455-465 1x2 bricks (loose) by my count.
One case of 1x2 bricks fills 6 heaping large PAB cups plus a few extra bricks. I have not opened the 2x4 or the 2x6 cases. 2x4's and larger are pretty easy to stick together in a cup so I suspect you will get less bang for the buck purchasing cases over sticking them together in PAB cups.
I hope this helps someone out!