For someone who surfs a lot (me) wetsuits traditionally last about three years/seasons. Last year my patagonia wetsuit was showing it's age and I brought it to the store. They sent it to their repair shop and the repair folks re-taped every seam, put new knee patches in and installed a new car-key-loop (original suit lacked one) free of charge.
The neoprene is starting to break down and the suit isn't as warm as it used to be. I anticipate I'll get this season out of it and maybe 1-2 more.
The company is fanatical about the quality of the products they produce and even more fanatical about their support/repair for those products.