Regarding a new ATA, only time will tell. Berettas & Brownings have always been built to a high standard (some will even say there are good & bad years) which results in them holding their second hand value. In addition they have good handling and can be very easily maintained. They also both look good despite very little changes over time. The 686 & 525 remain the the VW Golfs of the clay shooting world.
Regarding use there are so many factors. The gun must be maintained - replacing a part worn component avoids undue wear to others etc. This is very very inportant. Good cleaning is also essential to a guns long life. As a rule of thumb I was told (by a good gunsmith) that a 686 should do 250,000 cartridges if looked after. As Fred says this is 'should' figure - many, I expect, will do in excess of this number, because they have been loved. Some of the 'better' designs should do much more - a DT10 or DT11 almost 1,000,000 - a figure which CG now quotes for their Invictus line.
The game changer has been CNC manufacture and the quality this can now acheive at low cost. Less hand finishing is required and tolerances and reliability can be much higher. Some of newer Turkish guns are both good value and match quiality wise for more expensive guns. My only concern with them is the availablility of parts and ease of servicing. I expect this will change, getting better, as they become more popular and need servicing.
The best way to think about is the amount you shoot per year. For me its about 7,500. My 686E should therefore last me 35 years or so. There's an outside chance I may need to buy another one but if I get that old, and can still shoot, I will. Oh, hang on I have a "spare" 682 Gold in the cabinet and plan on a 694 in the next couple of years so . . I should be OK til 2120.