One thing that I learned from the sale yesterday was how fast things move. The pace is 30-40 horses per hour. There are no breaks, and you cannot call a timeout.
As prices were surging it was very difficult to quantitatively measure how things were changing. My guess of up 25% turned out to be accurate, but if I were playing with “live ammunition” I would want a better measure.
You really need as estimate of value for every horse in the sale, and well developed list of comparable horses that sell before your choice.
Buying A Race Horse 