John,
I was a Terry Redlin dealer for most of the first 10 years I had my gallery in IL. He is a much sought after wildlife artist and he has many many sold out editions. With that said, most of his editions were up in the high thousands which took them out of the limited edition range in my opinion.
His "Country Doctor" series was sold out within a few months of each of the print's issue dates. They immediately shot sky high on the secondary market and stayed there as did so many of his other editions.
If you have access to a recent copy of the Art Expediter or know of anyone in your area who subscribes to it, I would check the current prices for those prints in that listing. It is a much more realistic reflection of the current supply and demand for most of the popular prints on the market. I used it exclusively to buy prints on the secondary market and to set my retail prices for my LE prints when I was selling prints. There are other listings but they usually reflect someone's estimation of what the prints are worth. The Expediter will be a realistic price for whatever the current real world selling price might be and is driven purely by who has what and who is buying what ............... the old version of "supply and demand".
I would expect that you could find those prints separately for under a thousand dollars per, but a matching numbered set of all four prints will run substantially more per print. Those sets are very hard to find anymore as most of them were pre-ordered by dealers like myself who had specific print #'s reserved through Hadley House for any and all LE prints published by Redlin and other popular artists of the era. We had a standing order for those prints and they were generally sent unannounced to us as they were issued.