That's some pretty high mileage. The motor/battery warranty on that vehicle will expire at 125k miles, and unless they bought the 4 year 50k mile extended warranty, the bumper to bumper warranty is gone (and will be soon if they did purchase that). Personally, I don't think I would pay that much for a 2013 S60 with 94k miles.
If so - having the Rear Facing Seats does increase the value some (at least to people who want them). Still, with that mileage, and it being a 2013 S60, I personally wouldn't go over $30k, and I'd want the vehicle to have a thorough inspection first.
A 2013 S60 can't be upgraded without replacing the battery pack (not economically realistic). S60s seem to have a range of 180-200 miles. Whether that is short or not depends on the individualsi driving habits. I've had a Nissan Leaf for almost for years now, loving with an 80 mile range. So 180+ would be huge to me.