I'm not sure which came first, the SAK Soldier or the U.S., chicken and eggy, I guess... Though, I've seen some that are dated during the Vietnam era (and I believe they were issued/sold before that). SAKs are typically (in my opinion) easier to sharpen, but this has better edge retention. This is also very heavy duty (but not overly heavy), and quite comfortable. It's become my favorite pocket knife ever, and they are getting extremely hard to find for a reasonable price here in the US.
I paid $40USD for mine, as it was unused/unsharpened/unissued. More than I should have paid, but now I feel it was worth every cent.