He'd be nuts to accept that for it, there are loads of cars go for more than that on autotrader every week...
The general rule of thumb is that a mk2 derv goes for 180 money, plus a little extra if it has the kit!
I had a look at a few when I got mine (12 months ago), only two were under the 4k mark (mine being one), and mine was the only one without the kit... They all sold within a week of being listed on autotrader and before I got to them