I'm by no means a Luger expert, but I do have the Standard Catalog of Luger (Davis 2006), and I can find no listing for a DWM 1923 Commercial model.
Guns listed as 1923 models are the "safe & loaded" (rare, 7,000 made), the 1923 Stoeger American Eagle (very rare less than 1,000 made), the 1923 Stoeger "safe & loaded" (included in the American Eagle number), the 1923 Finnish Military contract, (approx. 6,500 made) and the 1923 Swedish contract (less than 1,000 made).
I can not find anything that precisely matches the specs in the linked picture.
If the gun is a 1920 Commercial model (which just happens to be dated 1923) it is a very common gun, and in VG condition was listed at $1,000 and good at $650 (2006 prices).
$950 in today's dollars for an all matching number, original finish good or better, Luger is a very good deal. If the gun has been refinished, and/or does not have ALL matching numbers, its only a fair deal, in my opinion.
Better answers on current value can be found with the Luger experts on Luger collector web sites.
I bought a reblued, mismatched 1936 gun (which looks brand new) for $750, but that was over 5 years ago. At the shows, "shooter" Lugers are around $1,000 currently (which is high), but, it's a seller's market. (and they tend to hang around at those prices,
)
Good luck!