Nice woody. Your example doesn't carry much value beyond what a '44 Wheat cent in circulated condition already has. There are some collectors who love woodies and might pay a little bit more for them--the more prominent the woody, the better. Check ebay for prices on sold Wheat cent woody auctions/buy now transactions.
Looking at it in person, I don't believe it is a stain. I'm going to keep it, so value doesn't matter much to me anymore with this coin anyway. However, I would love to know, are there ways to test if it is a stain or not? Or is it kind of a guessing game?