Well the crowdsale has to be in better price than market, otherwise why invest through BTTF. So short term price decline is logical.
actually, it tends to the opposity.
the price will be higher, that will lead to pump in the current coin and price will find a "new zone".
if they do a lower price in the crowdsale that will ruin the investors holding right now and that would lead to a lose of trust.
but, if they opens in a higher price, they market will adjust and that will be good to the current investors, and that will lead to gain trust.