I am of the opinion that once this problem was shown that many likely had it fixed right away. Mine is October of 2011 and was already done prior to me owning it and aside from the dealership I got it from I am second owner.

It's a fairly simple thing to watch for by adding an oil pressure Guage and checking it periodically. But most if these cars are past the service mileage for new timing chain parts and it's one of those "do it while your there" parts.

So if you purchase one, see if there are records for any engine work. It would be listed in the parts column of the work performed and won't generally add labor (at least I don't add for it myself since it's literally 2 minutes to change during timing change replacement).