To determine which of the two price ranges is better, you need to consider the following factors:

1. Market demand: Investigate the local market demand for light bottle liquor in different price ranges. If consumers are more inclined to buy cheaper wine, then the 13 yuan price range may be better.

2. Competition: Understand the pricing of competitors' products in different price ranges. If there are fewer competitors in the 15 yuan price range, it may be easier to attract consumers.

3. Cost consideration: Evaluate production costs and operating costs to ensure that reasonable profits can still be obtained from product sales in different price ranges.

4. Brand image: Consider your own brand image and positioning, and determine which price range is more in line with the brand image and the needs of target consumers.