That is nice. AFH was American Farm and Hoe. That is the original length for those bayonets. Bayonet doctrine had called for long blades like that back in WWI and earlier. Into WWII production, many of the blades were cut down to 10 inches and provided with new scabbards. That should fit a Garand.
There is a premium for uncut examples. Yours isn't quite as nice as some I've seen around, but the very clean examples sell for around $300. Most seem to sell between $150 and $250 depending on condition.