I also read that Vref is too high and have to admit that I only looked at it yesterday AFTER we made an offer for the plane which undergoes at this moment a pre-buy inspection at Cessna center. It is a inside and out not a like new but really nice 1966 Cessna 172 with 2x KX155 radios with a glideslope, an older King IFR GPS and a transponder. The aircraft total time is around 4000 hours, with around 1400 hours on the engine and prop. It was listed for $28,500, we offered $25,500, what the seller accepted.
Now, according to Vref the value would be $25,200. Frankly, to me this feels just about right. Despite of the relatively high time engine, I simply can't imagine that this is still too much for a nice 172 and that something around $20,000 would have been more reasonable!? I've been watching the market for quite some time know - the asking price of 'ours' was already rather at the lower end of the price / condition / equipment matrix. I find it hard to believe that a 30% discount on this (compared to other listings) reasonable asking price of $28,500 could be considered the norm.
Personally, I don't really care, because the plane is, except of the old GPS, exactly what we wanted (OK, we initially wanted a straight tail). I'd rather fly the plane we want today and pay a little bit more, than to wait for months for the ultimate bargain, which might possibly never come...