Costco hot dog combo stays at $1.50, and now you can have a bottle of water with it

The Costco hotdog, as depicted in promotional in-store material

Warehouse retailer Costco is famed for its $1.50 beef hotdogs, which come with a 20 oz. soda and haven’t gon up in price since its 1980s debut. Occasionally rumors of a price increase spread, only to be squashed by the company’s management; co-founder Jim Sinegal once threatened a previous C…