Your budget? Looking for wool, cashmere or cotton?
I really want a cardigan myself, but the only cardigan I really want would be a cashmere cable cardigan from Polo Ralph Lauren, and I think they are too expensive (seen them for $195 at eBay) for my current budget.
BTW I don't think you have to be 65 to wear the cardigan in your post, just make sure you have a modern pants, shoes etc. and it will look classic and nice.