is a 306 td l reg 122k in good nick worth £490

yes

yes i've just bought a 306xr, also an l reg for £350 and it goes like a dream. so try haggle him down to no more than say £450 (less if poss) and you've got a nice new motor. insure it before you drive it home though or get someone fully comp cause as l drove mine home l gotr stopped by the old bill and had to pay an extra £100 to get my car unimpounded another £200 to the cops plus 6 points on my previously untarnished lisence and i'm gutted

yes

Yes it a fair price, they have great diesel engines that when well maintained can go well over 200k, be carefull of the headgaskets going.