Once the Garands are gone there will be nothing left to sell.
Think about it.
Clinton already scrapped most of the M14's, and about every 1911 that was in gov't inventory. The M16 won't be offered, modifications or not. The American public won't allow it - and that includes a lot of shooters. Ask your older friends at the range - they get into a state of high conniption about "giving away full auto machine guns to crazies!"
I give the CMP about another ten years and that next liberal administration will be forced to close it's doors even if they were sympathetic. There won't be any more surplus firearms to sell.
I've been saying this for over ten years and nobody seems to care. They got theirs, the next generation can do without.
Like old soldiers, the guns are fading away.