In 1935, a single Dickson Patent Round Action cost 120. This is according to the Dickson catalog reprinted in Dallas's book.
1938, Abercrombie & Fitch quoted the following prices (all F.O.B. London):
-Boss Hammerless Ejector Over Under: 157-10-0
-H&H Model de Luxe: 157-10-0
-Purdey Hammerless Ejector "Featherweight" 12 gauge: 136-10-0
-Woodward Best Quality Double Barrel Gun: 126-0-0
-Churchill Premier Quality Doube Barrel: 120-0-0
This doesn't seem like a lot of money in today's terms. But in the 1930s 120 bps was a sizable chunk of change. In 1930 the US dollar was worth just over 4 schillings - and the pound sterling was 20 schillings. The USD equivalent to 120 bps was nearly $600 USD. There were a LOT of families in the USA that would have been very happy to earn $600 a month in 1930.
I recall reading the Shooter's Bible gun descriptions/prices and seeing a new Purdey listed at $1200 - this was in the late 50s! Things change, and the Brand Value of names like Purdey, Boss, and Holland and Holland has increased prices to provide high returns for the companies that now own these 'luxury brands'. In other words, you're paying extra for the name.