Average coin turnaround time in collections?

[Aleph]

What is the average time for ancient coins between market appearances?  I have recently seen a number of rare (not necessarily high value) coins in wildwinds and coin archives that have sold in the past 7 years or so and that I would love to have.  I was curious how long on average until these coins make a another eventual market appearance?  If this has been discussed previously, can someone provide the link.

[Valerius]

What is the average time for ancient coins between market appearances? 

It depends...what is the average life span? 

[Jeff Clark]

There is no set "average" time between appearances of specific coins.  There are a lot of factors involved.  I was able to buy a unique coin the second time around after only 4 years in private hands.  Other coins will likely not be available even after the death of the original collector as they may be passed on to other budding enthusiasts within the family or sold to specific collectors without even reaching the marketplace.  Then there are new found coins and the factors are even more difficult to measure there.  A common coin today may never be found again and rare coins might turn up enough to make them common.

[Aleph]

Sigh...
Thats pretty much what I was thinking as well.  Waiting for coins to reappear in the marketplace is like whale-watching.  Sometimes they come up 60 seconds later 10 yards from where they went down.  Sometimes you dont see them again.  All (well almost all) coins will return to the market eventually, but it seems to be after a totally random amount of time (months to decades later).  I do get a kick out of it, though, when you can connect a current coin to an old auction.  I was recently tickled to see that a coin on wildwinds (sold on ebay in 2003) looks like it was almost certainly in the Mabbott auction 1969.  I couldnt confirm as it wasn't photographed for the auction but the description is a dead match and the type seems to be extremely rare.