There are 2-3 blocks on Calle Murillo near the intersection of Calle Malabia that is just leather stores. Leather jackets, belts, shoes, bags, and whatever else could be made with leather - you'll find it here.

Quality varies. Taste levels vary. Consider it the outlet mall of leather. Come with a discerning eye and time to shop around.

If you want a leather jacket but you're on a budget, this (and the Sunday street market in San Telmo) is the place to start.