What was the price of guns in 1948?
Depends on WHICH gun. A basic .22 rifle may have sold for $10, but a higher end automatic shotgun or custom hunting rifle may have been several hundred dollars. One of the best sources of price information may be ads from old copies of hunting and shooting magazines that were published in your timeframe, and catalogues from companies that sold firearms. FWIW, your library can request a copy of the Sears catalogue from 1896. It is fascinating to look at the things for sale in 1896, and their prices- and yes, Sears sold rifles, shotgun, pistols and ammunition back then.