Today's M1's are collectables and there is a limit to the number that will be available. Plus the ones that are available are ex military, and the military aspect is desired by many shooters.
I loved the old Garand, still shoot a NM match version once in a while. I don't own a GI NM, I would not shoot a GI NM, because it is too valuable to glass bed, replace the barrel, and induce wear on the thing. However, I was able to have several National Match versions built around GI receivers and had Larry Barnett install his match barrels. They shoot well.
The M1 Garand and the M14 were expensive to build and are expensive to build. With CNC machining the price of a M1a machined receiver has dropped, but those are still more expensive than the alternative. A machined LRB is $859
http://www.lrbarms.com/m14-receivers--actions.html and a cast Fulton Armory is $549.00.
http://www.fulton-armory.com/m14-receiver-semi-automatic-fulton-armory.aspx Without casting technology I don't think Springfield Armory could have stayed in business with the M1a's. Even back in the 1970's, a fully machined M1a receiver would have been cost prohibitive, and the original cast receiver M1a's came with GI operating rods, bolts, sights, gas cylinders, etc.
Stoner did a great job in reducing the cost of his rifles, and as we can see, AR15's are much less costly than M1 carbines or M1 Garands, or even, M1a's. John Garand came up with a great design but "design to cost" was not a real consideration before WW2. After WW2, it was, particularly for the Germans who lost entire Armies and their equipment in Russia.
Recently just read of a "forgotten" battle where either 500,000 Germans or Russians died. I expect most of their equipment was also lost. Their were 800,000 Axis dead at Stalingrad, and the dead, along with the survivors, lost all their equipment. Battles where half a million soldiers die put a huge strain on the ability of any nation state to raise new soldiers and equip them. The HK91 is an outstanding example of a rifle designed to be reliable, easy to maintain, and cheap to manufacturer. I think the Germans decided it made more sense to focus on production, so when I look at my PTR91, I don't think depot maintenance was a design consideration. The barrel could be pressed out, but I think, the Germans decided that worn out weapons should go on the scrap heap and no labor be diverted to rebuilding worn out rifles. Just punch out new ones faster and cheaper, I think that was the philosophy.And it is no coincidence that the HK91 is the only 7.62 Nato rifle still being made and issued as a service weapon.
I earned my Distinguished Rifleman's badge shooting the M1a out to 600 yards, earned enough leg points to stand on the stage and be handed my Distinguished. I love the rifle, have a great respect for the Garand. But, the things are not cheap to build, or own!