I *think* most of them are WWII vintage but I am not an expert on the platform and I cannot readily tell from a quick glance how old a rifle likely is.

I already have an 1943/44 WWII M1 carbine which I purchased in 1994 for less than $250 (in really good shape). The ones I browsed today were generally not in quite as good of shape as mine. And some were even a little rough. Prices ranged from $1,000 to $1,300, depending upon condition and manufacturer. 10 different companies manufactured the M1 carbine during WWII and approximately 6.2 million were made (some of those post-war, I believe).

Really cool rifles with one major drawback (in addition to their current prices). Ammo is really expensive. Generally around $0.75 per round. As a platform, the M1 carbine just doesn't make much sense these days when solid AR-15s can be had for around $400 (and .223 or 5.56 is relatively cheap). But everyone should probably have one as a collectible.