My fare went up $10 since yesterday, so I ticketed it now (the J fare, since fully refundable).
Note also that at least on the JRXPP fare basis, there is a senior fare (60+) available which is 85% of the fare. You might need a travel agent to get you that one, as I don't see that you can specify anything "senior" on the AM website. Worth a TA service fee for that one.