Start high? This isn't some street market in the middle east.
Ainge asked that because he wasn't interested in trading Allen at that point. There's no reason why the price of the players, including Ray Allen, goes down linearly till the trade deadline. That's nonsensical. The price of some guys may go up, others may go down, others doesn't change at all.
Bird just stated the obvious - so far, Ainge isn't showing interest in trading Ray Allen. Maybe because he wants as much time as possible to evaluate if he wants to keep this core or not. Maybe by the next couple of days he decides he doesn't want to keep this core and lowers Ray Allen's prices. That doesn't make what Bird was being disingenuous, unclassy or taking a hit. If Ainge wants to trade Allen, he'll lower the price. When he was talking to Bird, he wasn't keen on moving Allen.