It's an early gun. Since Walther's official production run started with AC 480 guns, which then switched codes to AC40, AC41, etc etc until the end of the war.
Price will vary on condition and which block the gun is in. AC40 guns went from althe way to 9999a to 9999b. Ive seen early "a" block guns all matching mint bring almost $2k on a buyers market. Depending on the block and capture paper along with condition yours may bring as much.
Definately only early P38s bring good money, every other one is only worth $700ish.