Microsoft dropped to $249, Sony didn't budge off of $299. They then moved down the price to $199 when Microsoft did, because of tension. It's a flash price change. Sony then moved the price from $199 to $179 a day earlier than Microsoft when they learned of Microsofts intent.
That one was definately a flash price change as retailers had no POP materials for the PS2 change but had them for the Xbox price change. They didn't want Microsoft to lead the price change war. If Xbox wasn't around, you'd probably bet the PS2 would be priced still fairly high. It's not on their own timetables. All their price changes were based on Xbox's because of the market tension.