Are both sentences OK?
We should make a lesson out of it. (a story etc.)
There's no prices on the menu. (in a restaurant etc.)

Question

Are both sentences OK?
We should make a lesson out of it. (a story etc.)
There's no prices on the menu.  (in a restaurant etc.)

Answer

The first sentence is correct, but in the second sentence "there is" should be replaced with "there are" as the subject is plural.

Answer

The first one is okay (completely understandable) if you’re speaking casually.

The second one would be, ‘there are no prices on the menu.’