There were thousands of M-1 Garands and Carbines headed back to the US from South Korea recently, but the Obama administration stopped the sale.
I would look at gun stores that sell used rifles. My local gunstore has 3 for sale. They aren't cheap. Most run $890 to $1000 dollars for and M-1 Garand, I would bet that the carbine is pricey also.
Here is an organization that refurbishes them and sells them to the public cheaper, but you must qualify to be part of this program.