From what I can see the full value in a refurb is still not reflected in the selling prices. IMO the very best deals are in purchasing an aircraft that has already been done.
On a related note I am becoming quite concerned about the fact that the GA supply chain is drying up. Many parts are now available only from a single vendor and prices can be all over the map or a critical parts are simply not available at any price.
A Friend of mine has a Cessna 340. On the last annual it was noted that the heating element on the stall warning vane was looking rather tatty. The first though was to just replace it until it was learned that a new one cost $ 7000 US
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Now this vane is the exact same little piece of bent tin you find on any small aircraft with an electric stall warning horn like a Pa 28. The only difference is it has a small heating element glued onto the exposed part. A 1980's vintage parts catalog from Cessna listed it for $ 107.11
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The more complicated the aircraft the more little valves, switches, actuators etc it has, some of which go for just silly money.
So the refurb is still just the start of the spending. Keeping the higher end airplanes going is getting increasingly expensive. BTW my friends aircraft is from a mechanical view point probably in the top 5 % of C 340's yet he still budgets $ 50,000 a year for maintenance.