That chart is full of bad information. The 00-grade L.C. Smith was a $25 gun. It was a $50 gun with ejectors, an 00E-Grade. Many companies from the 1890s to WW-I showed a high "List Price" in their catalogues, but the guns actually had a much lower "Net selling price." The Remington K-Grade early on had a List Price of $35 but a Net Selling Price of $25. Same with A.H. Fox Gun Co.'s Sterlingworth, List Price $35 and Net Selling Price $25. From the 1911 A.H. Fox Gun Co. catalogue --
Likewise the Lefever DS-Grade was catalogued at $37 but is shown in magazine ads as a $25 gun.
The country entered into a steep inflationary spiral in the lead up to and during The Great War. For 1916 the price of the Sterlingworth went up to $30 and for 1917 to $37.50. By early 1919 a Sterlingworth was $47.75 and by late 1919 it was up to $55 where it stayed into 1922. The chart lists a Sterlingworth Deluxe in the $40 bracket and the colume is headed 1916 to 1929, when there was no such thing. The Sterlingworth Deluxe was introduced by Savage Arms Corp. in 1930.
The HE-Grade Super-Fox is listed in the $50 bracket. When first introduced in 1923, it was priced at $125, but quickly dropped to $100. For 1925 the price dropped again to $85, and by 1927 had dropped to $79.60 where it stayed until Savage dropped the price to $66.50 in 1930. Savage upped the price to $72 in June 1932.
The date under Remington is 1912, and they had been out of the double gun business for two years by then.
I could go on and on. I know how hard it is to do a comparison like this, as I tried in my Baltimore Arms Co. article in
The Double Gun Journal.