Around here league lineage runs $8.50 to $10.50 depending on the center.
League fees for adults go from $10 up depending on the prize fund size.
I’m not a proprietor but I’m amazed they can provide bowling that cheap. And if they were making money hand over fist (like they did in the 1960’s) new centers would be opening all the time.
If you look at cost of a lane bed, utilities (heating, cooling, lights, running the machines, etc), labor, insurance, taxes, pins and maintenance cost to machinery the numbers get big very fast.