This is the cheapest delivered price I have found, next cheapest I have found briefly is ebuyer £42.57 delivered. Most places sell for £45-£55.
This is a compact laser mouse, with presentation remote control, laser pointer and runs over bluetooth.
Product Description: Microsoft Wireless Notebook Presenter 8000 - mouse
Device Type: Mouse
Connectivity Technology: Wireless - Bluetooth
Wireless Receiver: USB wireless receiver
Movement Detection Technology: Laser
Buttons Qty: 5
Movement Resolution: 1000 dpi
Features: Programmable buttons, zoom wheel, laser pointer, scrolling 4-way button, Tilt Wheel technology, High Definition Laser Technology
OS Required: Microsoft Windows XP SP2, Microsoft Windows Vista
Manufacturer Warranty: 5 years warranty