Graybeard is correct about commemoratives that have been fired. However, the 1885 in .45-70 is getting prices of $1,000-$1,400 used in like new condition. Especially the Traditional Hunter in .45-70. I'm not familiar with thw specs of the NRA .45-70, but if it is similar to the Traditional Hunter, the price of $1250 is right on the money. If it's similar to the Creedmore 1885 model, then it's low. If it's similar to the standard model 1885, then it's a bit high.
Hope this helps.