I often see Cadets in the $500 plus range that are at best just shooters. Many 303s and 577/450s are in sad condition and prices in the 500 dollar range and above. Good shooters are nearing $900. My recent purchase was $450 which, for this particular gun, I felt was a fair price. I have picked up a couple Greeners for $200, but neither was shootable when I got them and had mechanical issues. Parts for Martinis can be scarce and are crazy priced. An example is recently there were 2 Cadet actions on Gunbroker that were sold for well over $600. I tried for 2 months to find an extractor for my Greener that I converted to 38-55 until I finally made one from scratch out of frustration.
Edd