There was a fairly extensive ER article a few years ago about the BC348.  The author included pricing after the war into the late 40's early 50's.  It actually went up in price as it became more popular as ham's discovered how good of a RX it was,  and many could be had in original packaging from the manufacturer, never having been opened.  The main thing I found funny about the 348 and 342/312, is the 348 being significantly lighter.  I remember the first 312 I ever picked up after only handling 348's, and my first thought was if they only put this one in a tank.

Charlie in NC