It's a two year old phone and one that will no longer be supported in a month or two.
I'd pay a bit extra and get a 3GS or more likely, wait and get a 4th Gen.
But to answer your question, £200ish.
Scrap that. I got ahead of myself. It will drop it for the 1st Gen
I'd still avoid the 3G. No multitasking. Plus its sloooooow.