At roughly 88,000 miles, my Rohloff started leaking a significant amount of oil from both the drive and ex-box sides. The hub was running just fine, but it seemed pretty clear that it was time for new seals at least. Peter White Cycles (where I purchased the bike new) told me that "Rohloff guidance" for a hub with that mileage was to pull the entire core and replace it with a factory refurbished core for $350. Since there was no way that I could see to get replacement parts I (begrudgingly) had the replacement done. 3,000 miles later, the rebuilt hub seems to be doing just fine, thank you. On the plus side, no leakage at all which is better than the old hub even when it was brand new.
Bottom line, I paid a couple hundred bucks more than I should have needed to for new seals. But if I can get another 80,000 miles, I'm not going to complain too loudly. The cost per mile, even including the cost of new innards is still about half of what my various derailleur bikes cost. I'll pile on here and say if it ain't broke don't fix it.