great idea. i dont need AD tho, gray market is fine, as long as its someone i trust.
I have a great memory for numbers (be it watches or cars). I also save all the reciepts for every watch I've purchased. Although, recently I got rid of reciepts for watches I have since sold/traded.
Serial number prefixes can give an estimated date of prodcution but its not exact. The old T < 25 was in reference to the use of tritium (less than 25 millicurie). Around 1999/2000 they stopped using tritium and switched to luminova...hence the change taking T<25 off the dial.
The Triplock crown always extends past the shoulder on older Subs (I haven't specifically checked this on the current models). My 2005 Sub Date with green bezel does the same thing (crown extended past crown protector shoulders).
Even if those things are accurate, it doesn't mean its the real deal. Make sure you know who you are buying from, so you don't get screwed. There are lots of Subs out there. If you don't trust this seller move on to another.
I'm not a watch buff, but all this talk of rising prices got me thinking: perhaps it's not just profiteering, as the Swiss Franc has been historically very high against both Dollar and Euro over the last couple of years. The Swiss Central Bank did dump the currency about a year ago and reduce its value by about ten per cent again (an emergency measure as the high value was really hitting their industries hard), but nevertheless the Franc remains relatively expensive. Bear in mind also that some high value and labour-intensive products in stock with dealers now - like high-end watches might have been ordered at prices before the big re-alignment of last September.