Each chop produces 2 firewood at no true cost to the Dragonborn, other than the need to have a woodcutter's axe in their inventory. Each chop is estimated to take 10 seconds, and the Dragonborn stops working after 3 chops, estimating 6 chops in a minute, 12 pieces of firewood in that minute, and roughly 720 in an hour. An hour out-of-game is estimated to be 24 hours in-game (2.5 minutes = 1 hour). This means in an hour, the Dragonborn can earn 3600 at no cost but the time it takes.
Employers for woodchoppers purchase all firewood in the Dragonborn's inventory at once for the base asking price. Each wood chop produces 2 pieces of wood, each piece of wood is worth 5 gold each, and also weighs 5 pounds each.
Chop wood, mine ore, and cook food