Strange prices at Johnny Rocket’s

Ben Daniels writes to me:

Seen at Johnny Rocket's near LACMA:

Pancakes. Delicious buttermilk pancakes, served with bacon or sausage & warm syrup.

Two pancakes 4.99  

Three pancakes 4.99

Error aside, how might we account for this?  One option is that the company wants to give the "three pancake consumers" the sense they are receiving a bargain.  I suspect, by the way, that the marginal supply cost of an extra pancake is quite small.  The extra pancake may also increase your demand for high-margin beverages.  What else might be the explanation?