The price is not very much different from any place else you would get a shake from.
Maybe they are a little higher but ohhh they are worth it.
As a local guide, I can only tespond to question I know. I've never had a shake from Whataburger due to a milk allergy. However, on their website, http://whataburger.com/home/contact, There are several ways to contact the CEO's, corporate headquarters and even a customer service number if you want to ask them or make a complaint. I regret that I could not answer your question.
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