I would take it to Mr.Transmission first, they will hook up the car to a computer for a 10-20 min drive which will monitor all the transmission sensors for any faults. If that doesn’t provide answers they’ll hoist it up and check a number of parts including line pressures etc… Remember to visit the exact address i listed, theirs lots of Mr.Transmission shops and i can only vouch for the one i told you.
The Transmission does not need to be rebuilt, this harsh 1-2 shift is not a terminal problem for the transmission, in most cases it’s caused by low tranny fluid or badly oxidized fluid. I have friends that have driven well past 180,000km with the problem, you just need to change the transmission fluid every 25,000-30,000km and remember to not flush it just drain and refill.
If you really just want a new transmission then open a case file with Nissan North America, complain and complain like their is no tomorrow. Remember Corporations respond better to threats, when they have something to lose! Being a small business owner, i lease/own 7 new Nissan vehicles and threatened to bring them back if they didn’t bow down lol. They eventually coverd the cost.
Hopes the helps. 
Mojo728