JWCRET - first off, welcome to the fourm. Second, without trying to sound like a jerk, your question can't be answerd as-is. The value of any firearm depends on different factors, such as rarity and condition.
Literally millions of M1 carbines were made during WW2, so just having an M1 Carbine wouldn't be unusual. However, so many (the vast majority) went thru government overhaul and rebuild programs that finding an original, un-touched, unmodified M1 Carbine is getting to be pretty rare.
Then there are the 'restored' M1 Carbines (and other weapons). When you get to this piont you are starting to tread on shakey ground. Maybe even shakey legal ground if you are involved as representing the piece as an original to jack-up it's collector value.
Other than that, a simple answer that out here on the plains of eastern Colorado, a shooter M1 Carbine could be had for $400 to $600. An untouched, original unrestored collector M1 Carbine could fetch $1000 to $1200 without much trouble. Your best bet is to find a collector's guide. M1 carbines are just plain fun to shoot. Back in the days of cheap ammo if you were going plinking, a Carbine was always my first choice over any .22 made back then.