Popular magazines make most of their money through ad revenue. This helps keep their subscription prices down. On the other hand since very few scholarly journals contain ads, journals make most of their revenue from subscriptions. Journal subscriptions can range from $100 to thousands of dollars. This is why you find scholarly journals in libraries and not chain stores like Walmart. Some journals are so expensive, that only very few libraries can afford them. Look at the difference in prices below:
In the above graphic, you can see that The Journal of Comparative Neurology costs $35,866 a year (higher to receive both print and online versions).
That's more expensive than the starting price of a 2020 Dodge Charger ($29,470)!