I would say it is worth around £165 (about $268 american dollars), but it depends on the condition of the games you have and if they are popular games I would say if it is in good condition and has popular games you would be able to get around £180.
I looked it up on ebay and this bundle is on there for £184 but remember this is new
http://cgi.ebay.co.uk/Brand-New-60gb-Xbox-360-console-with-9-Games_W0QQitemZ220302262541QQcmdZViewItem?hash=ite m220302262541&_trksid=p3286.c0.m14&_trkparms=72%3A 1297%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318
EDIT - IT WENT FOR £205
I hope this helps to answer your question

Were you just asking or are you actually going to sell it if you are I would reccomend Ebay or one of the game shops like game station and Game.