Infinite scented markers. Lemon and berry and cinnamon and clear scent. In marker form. Never lessening, never running out.
Walking around with these in your pack, you'd be more popular than the kid with dolphin skin.
And I can get you these markets that smell of food. I can even get you one that smells like Formica. Oh, it's a wondrous world, looked at in the right way.
All you have to do is bring me that infernal shepherd's head. And, of course, the copay.
Which is, really, very reasonable.