Each area is different. I did a search on dreamhorse and for 3+ year olds in my area for less then 1000 it came up with over 350 within a 75 mile radius.
There is almost no market now. It looks like this mare has been for sale from at least October. In my area she would not even be looked at unless she was under 1000.
I have a 13 yr old mare that I rode competitive, has won CMO rides, does 2nd and 3rd level dressage, spins, does rollbacks and poles and barrels. I have her for sale (divorce) for 900. She is traffic and trail safe, my 12 year old can ride her. Really nice balanced responsive mare.
There are lots of horses still priced at the old prices but unless they ind a greenhorn sucker they are not selling for those prices anymore.
Well trained well loved horses are being given away or selling for a few hundred.