Antec, Sunsonic or so . . . . nothing below 40-50EUR for a 300/350W PSU.
Mine is a "Sunsonic SS-250SF Active PFC" but no more produced (IIRC its available the 300 or 350 watt)
Take a look to some online reseller.
RS-Components has the 350 watt one (uhg!!! 73 EUR)
Goto
www.rs-components.com, chose your country and type in the search string
ss-350fs OR ss-300fs
EDIT- just checked . . . Germany is cheaper than Italy :-(