How much is a 1943 wheat penny q mint worth?

I don't know where you found the letter Q on it, but that's not a letter for any US mint. For a 1943 cent (and all Lincoln cents), the mint mark is located directly below the date. Nothing there means it was minted in Philadelphia, a D means Denver, and S is San Francisco. No steel '43 cent is rare or especially valuable. Most are worth around 10 cents, and perhaps upwards of a dollar if the zinc plating hasn't worn away.