I actually picked up the last win xp version for £136.49 inc del.!
The versions left have windows 7. You need to choose Inspiron Mini from the filters on the side.
The list refurbished price is £149.33*1.175 = £175.46 but use the code DJ3QBP1WNC2SLN to bring it down by £20. Free delivery this month as well.
Even at £155 I think its a good price considering these are around the £200 mark on ebay.
This is apparently very OSX friendly which may account for the high resell values. I will also be giving this a shot.
Don't know if quidco will work? Mine hasn't tracked yet.