Check with your John Deere dealer for an A&I seat price that they can order. Although the A&I seat is a little bit different in appearance (doesn't have the same cover to base retaining method, or the button hole drains at the back and the base is plastic and doesn't have a JD logo on the back), I thought the A&I seat sat better (with my girth in it). The seat comes with a note to use standard hardware to retain it and will fit right up. As I recall it was also priced in the ~$70-80 range.
Even though I have purchased several of the correct regular John Deere seats in the past, I have never been satisfied with the cover retention edge guard in the long run. It always seems to work off after some time. Also, inevitably the seat cover cracks at the corners.