Why the big difference, to hit $1,800,000? It could be:
Two rich determined people wanted him. After $400,00 there were only two bidders throwing punch after punch. Lots of rich people have the “I will not be beaten” attitude.
He is a well-bred colt, Smart Strike is a well-established top class sire, and his dam, Mini Sermon, was a Group 2 winner, and placed in other Group races, from a family containing other Group horses.
The six months development (and shaping) since its previous sale is 25% of its life so far. That work input at that time prior to a Spring Sale as a two year old, can make a big difference. By all accounts he was the best looking horse in the sale and had the most visits at preview.
He ran a sub ten-second furlong at the breeze-up for the sale. Its a positive to be well-bred, it’s a positive to be good looking, but it really helps to KNOW that the horse can run fast.