The 312 and 344 seem to have been  produced in less numbers than the 224 and 348, if you just judge by remaining numbers. Unless a whole lot of the ground receivers went "somewhere". 

I have never ever seen a 224 - 348 rec sell for $200. I would say way south of $100 for sure, at a hamfair swap out here on the Left Coast. Maybe on Ebay. 

Looks like first step for any civilian user: "Remove those toilet seat covers". 

I am sort of surprised the GRR-5 was still in Army use even when it appeared in the Surplus Schematics Handbook. But Jimmy Horn said when he was in the Navy and the APX-6 was still in use and classified, he saw one in the window of a CA surplus store.

-Hue Miller