if you get everyone to put their sell orders at $450, there will simply be less coin on the sell walls, making it far far easier for the price to rise. i truly find it funny when people dont realise that if they have coins on the exchange, it is there own actions causing a price drop. and the simple solution is a consensus that no bitcoin should be sold below $300, making every bitcoin worth atleast $300.
but then again trying to break through the natural panic emotions of naive traders, and get them to go against their natural mindsets is the problem
People are willing to sell for less. It is their right in an open market.
What you're asking for is price collusion.
tsk tsk