Yes - you did well.
We talk a lot about the good old days when redemptions were fixed. On the high end those days were definitely better. But on the low end it's not always true. IIRC, way back a domestic round trip was 30,000 miles. Then the Skymiles program was created and a domestic roundtrip decreased to 25,000 (maybe I have that backwards - but that change also changed the minimum segment accrual from 1,000 to 500). But back then there were many flights when no mileage seats were available. By that metric you got a domestic roundtrip for 20% more than it cost 35 years ago - that's a pretty decent deal.

There will always be others who found a better deal but you didn't go online to find the best deal - you went online to get from SLC to PHX and back. And you accomplished that so sit back and think about the money you saved and don't second guess yourself. Remember, comparison is the thief of joy.