Actually; this has been talked before in forums; even by BB members that prices that people are paying currently  for lvl 5,6,7 trainers (500K-3 million)are simply too much. And too much to return on investment.
Like in real bull markets; it is up to the guy who would be willing to pay. But yes it is too much at this moment.
For what it is worth; I would never go up more than 300K. 
                                
                                
                                
                                
                                
                                
                                    yesterday is history, tomorrow is a mystery, but today is a gift. That is why it is called the "present."