How much should i sell my laptop for compaq presario cq60?

I have a august 2009 compaq presario cq60-419wm which I upgraded with 4gb dual channel memory, 300mbps wireless N card, vista ultimate media center edition with sp2, ms office student & teacher 2003, better memory timings & clock speed, updated bios, fully up to date & a few extra profesional programs, faster & more stable than my friends 1 month old $1000 toshiba laptop, I know this comp sold for $298+tax $350 or so out the door but my mom paid $400 with ms office on it from a shop in 2010 then I upgraded it with a couple hundred in parts & programs so what can I sell it for now? Thanks!!