Ohh my gosh. It sounds like black friday at walmart. I hope no one got injured :-).
That's a very strange set up for a sale. I don't think i would like that! 
Oscar
Oscar, thanks for the advice on the loose soil to tell if it was newly potted. The setup was actually pretty good, we may not have done a good job of explaining it. It was well run after they got the "bugs" out of it. It was an area about the size of a NBA size basketball court. The plants were organized in four rows. Customers were given a map of where different species were located, so you could find trees. The potted plants had a price tag stapled to the pots. The back side of the tag said which nursery provided the plant. There were three or four cashiers where you could pay for purchases, using only cash or check. The tags were made, so that a portion would be torn off at the time of purchase, so the sellers could be paid, etc.
I went two times during the sale and had two totally different experiences. My first visit...I showed up around 15 minutes before it opened and there was a line of about 20 people ahead of me. By the time it opened, there were about 30 people behind me. When it opened, there was sort of a stampede. It was crowded, people were rushing to get what they wanted; it was a bit chaotic. There were no carts available, unless you brought your own. As a short cut, people would cut thru the rows of plants, sometimes trampling the plants a little. I asked a volunteer to help me, he helped me pick out a few plants, but then someone else lured him away. I put my plants in the holding area, where I went to get the rest of the things on my list. I bought five plants and a bag of fertilizer. At checkout, I paid with cash. The cashier (an elderly volunteer) "tested" the money with a black ball point pen and thought my money was counterfeit (it wasn't). Another volunteer politely pointed out that the cashier had used the wrong pen to test the money. In fairness, I was probably one of the first people to check out, so they had not worked all of the "bugs" out.
My second visiti...a friend wanted to go to the sale later in the day, so I went with her around noon. It was a different experience. It was no longer crowded. There were more volunteers than customers and volunteers would ask if they could help. Some volunteers had carts to transport plants. There were a lot less trees there, but you wouldn't have known except that I had been there earlier when there were a lot more. They were out of fertilizer. I bought one more plant, my friend bought two.
