- How much is / are a dozen egg?
According to this website, american english - Does modifying a collective noun with a number make the subject plural? - English Language & Usage Stack Exchange it should be
“How much is a dozen eggs?”
I take it we are talking about how much a dozen eggs costs?
Yes, I think the alternative phrasing would be “How many eggs are in a dozen?”
“How many eggs are in a dozen?”
“How many eggs are there in a dozen?”
Do the sentences have the same meaning?
Though both the sentences would mean the same, the second is the better of the two in a formal context.
But, logically, the word ‘eggs’ does not have any relevance since a dozen, whether it is eggs or elephants, will always be 12. If so, How many are there in a dozen? would be still better.
To answer the original question, I agree with Luschen and say: How much is a dozen eggs?