> Are customers that aware of price increases?
Yes. This is exactly the question answered by the concept of supply and demand curves. Of course you can argue about the shape of those curves but their existence is not in doubt.
Supply and demand curves don't address the customer's awareness and perceptions at all price increases. Sure if the price doubles, they'll notice. But a 5-10% increase in something infrequently purchased would not be noticeable to the average consumer. Now if it's something they purchase everyday? They'd notice a penny increase.
Restaurant sales are rarely made up of price conscious buyers. Sure there's a limit, but short of the blue light special crowd, most customers are eating out for either variety, social reasons, or being tired of cooking.