how much is this laptop worth?

[timetosmile]

My son wants to sell his laptop to a friend, in order to put the cash towards a gaming computer.....
....so I told them I would ask you nice folk what you thought would be a fair price?
It's a HP Pavillion g, I think about 4 years old and has windows7 and all the usual office-type stuff on it giving myself away utterly as a non-geek
Its in good condition and works properly, I've posted a photo.

Thanks for any suggestions

[MrsSpencerReed]

£200 seems to be the going rate on eBay.