Looking back to the Maryland DNR site again, I see that the information inconsistent. The site refers to fees that are "reciprocal for state of residence", however this applies to the annual fee. They then link to a chart that contains the reciprocal fees, but this chart contains columns for 3-day and 7-day licenses as well. Maybe the Walmart guy was not the only one at fault. In any case, I've never seen this type of fee arrangement anywhere else.