I think you're being sarcastic Ging, (text is difficult sometimes)
but just incase you are somehow genuinely asking then I would say that mileage not age would be the best judge because Gore tex is a membrane, not a coating and so while you may expect a coating to deteriorate over time even if not being used you would not expect the same of a membrane.
so if you've done mega thousands of miles in those 5 years then the membrane may have been flexed so much it has given in and that would be value for money.
but if you've only done that 50 miles in 5 years and they've leaked then id suggest an inherent flaw and not buy another pair
that's foccin science yeeeee haaaaa!!!!