In terms of being the consumer, you would want the best in a product, so quality.

In terms of being the seller, you would want to sell the most products, so you would want to go with quantity. The more you sell, the more money you get.

However, you can't have both. With a high quantity of a product, the quality will be low. But a high quality product would be low in quantity.

I would go with quality, because it's a guaranteed thing.