At the Gamer's Day event in San Francisco, Sony revealed the prices for various peripherals. The Sixaxis controller will be $49.99, which is the same price as the wireless Xbox 360 controller and $10 more / less than the Nintendo Wiimote (depending on whether or not you include the nunchuk add-on). The age of $50 controllers is very frackin' nigh.
The PS3 memory card adaptor, that allows you to transfer PSOne and PS2 memory card data to the HDD, will only be $14.99. The BD Remote Control, which is "coming soon" (read: not available at launch) will be $24.99.