Microsoft Store offers the Razer DeathAdder Essential Ergonomic Optical Gaming Mouse, model no. RZ01-00151400-R3U1, for $39.99 with free shipping. That's the lowest total price we could find by $19. This right-hand ergonomic mouse features 3500 dpi, a 7-foot cable, scroll wheel with 24 click positions, and gold-plated USB connector.