For how much should i sell Socom: Confrontation for PS3?

May be...

I'd guess between $20-$25 depending on the condition of the disc, manual, and game case !

well off ebay you won't get much for it i say 15-25$ tops its better if you trade it on goozex.com there is a link on my profile

Not very much, I worked at a used video game store, 20 dollars the most.

25-30ish dollars

My buddy just sold it on ebay for like 23 dollars like a day ago.

RRP is $50

so maybe $25 - $30 ebay