I'm planning to travel from Central CA to Albuquerque, NM mid-May. A couple of weeks ago I found discount code V851 that made the rate $161 round trip. Went to book it today and the code is now for much less...I've spent an hour trying various codes that I could fine online. The V851 is still the lowest, but the trip is now $210. I'm kicking myself because of the extra $50.
Anyone have a code that might work in this area?

I'm traveling alone and not spending the extra for a sleeper.
Thank you!
Cheryl
Welcome to FT, Cheryl!
Unfortunately, if the code isn't listed on the first page of this thread, then none of us here knows about it. I don't see any that would apply to you other than the one you already mentioned (which actually isn't listed here, so nobody here received any info on it!) and the standard AAA, etc. discounts.
In the future,
always book your tickets as soon as you've got a reasonable idea of your dates. Amtrak tickets are always fully refundable and changeable (although if your tickets have been printed on paper ticket stock, there will be a 10% fee for refunds but no fee for exchanges).
For now, I would suggest booking the ticket with the V851 code you have and then keep checking back for any different codes issued or discovered between now and your trip. This will keep your trip's price from going up any more. However, even if a better code comes out between now and your trip, the total price may be higher than the current price because more seats have been booked and Amtrak's price goes up when more seats are booked. If you do find a lower fare or a discount that makes the total price go down, you can always rebook and get a refund for the difference.
Hope this helps!