Easy money?

Currently the fishing shop in Lumbridge sells feathers for 6 gp each, and there is a regen limit of 1000 on these. Feathers currently sell for 24 ea on the GE, making this a profitable investment. There are a lot of people who are world hopping to get them though, so after an update would be the best time to hit these up, or you can try world hopping yourself. Up to 18K a world hop isn't too bad, but I've just been buying whatever stock the store has when I'm in Lumbridge. It's still a lot of effort for a small amount of money, but the profit margin is ridiculous.