So, using common sense: ask yourself - " If they were the top-of-the-line product/technology 2, 3 or 5 years ago, and they are in good shape (excluding grips) and to your swing specs, what would disqualify them from going into your bag? Technology cannot be so superior today vs 2-5 years ago... be aware of your iron lofts (your current set) vs what you are considering, as OEM's are delofting at an increasing rate to claim "...the longest ever _____", and they really aren't.
IHMO, unless you are a top 1%'er golfer, you're not spending your money wisely always buying new.