Quoted from Onwallst:A TZ sold locally for $8900. The guy who bought it as his first pin and wanted a HOU one as it was pin he played when in college. The seller sold on Craigslist in less than 24hrs. I think it is crazy but the buyer and seller were happy. The free market always wins.
Your example is only one of the free market winning if the buyer was aware that they were over paying for that TZ. Otherwise it's an example of the seller capitalizing on the buyer's ignorance.
Helping buyers make informed decisions is exactly what responsible friendly pinheads do. A new buyer is more likely to be ignorant of market conditions and potentially get screwed by someone.