Final answer:
The cost of substituting a blueberry muffin for toast is not provided in the reference material. Charges for such substitutions depend on various factors and are set by the establishment. Consumers make such choices based on health, preference, or budget.
Step-by-step explanation:
The cost of substituting a blueberry muffin for toast in an egg dish is not explicitly stated in the provided reference information. Normally, in a restaurant or cafeteria setting, additional charges for substitutions are decided by the establishment's management based on various factors such as cost of ingredients, demand, and pricing strategy. If one were to make an educated guess based on common practice, one might assume a nominal additional charge for a premium item such as a blueberry muffin compared to standard toast. Typical upcharges may range anywhere from $0.50 to $3.00, depending on the cost of the muffin to the business and the perceived value to the customer. However, without specific pricing data or guidelines from the establishment in question, providing an exact cost would be speculative.
In lieu of precise data, consumers often make substitution choices based on health considerations, personal preferences, or budget constraints. The references provided do suggest a lean towards healthier eating options, which may justify a possible substitution cost due to the nutritional benefits that blueberries confer. For accurate pricing, it would be best to consult the menu or contact the establishment directly.