I agree to the latter without having bought something in Italy.
Paid 7,50â‚¬ plus shipping for a Logitech RX250 (OEM).
I a retail store (the "legendary" Media Markt here in Germany), I paid 9,90 for a MS Basic Mouse in Retail package. There are also cheaper mice, but these are usually lousy (but with blue LED illuminated mousewheel).
@kg_evilboy: I'd suggest looking in the 30 cm shelf level.