Problem is everyone wants stuff for dirt cheap!! Purely as an example, you could have two early DE's being sold one at 5k and the other at 6.5k. The 5k car within the first 12 months will need 2.5k spending on it (and the potential buyer knows this) ie clutch, flywheel, tyres, brakes and exhaust. The car advertised for 6.5k has all these item replaced recently, so on that front nothing to worry about. Folks would still rather buy the 5k car and cheap out on the repairs or allow the items to become MOT failures going forward.
BUY THE 6.5k CAR INSTEAD!!!!!! This is whats hurting the values imho, cheap A$$ people using poor man math.