I'm the helpful merchant whose shop is in a very populated and easily accessible area. My goods are shit but I have infinite money so you can get rid of your over-encumbrance and sell me all fifty of your leather gloves and short daggers.

Alternatively, I'm a completely unimportant merchant who happens to sell a unique item, so all the perfectionist gamers need to go back and scour through the entire game again to find me and buy that item.