I find it interesting that in the original post there is an implicit motive to try to get working class people to spend their money "like the rest of us," of sorts. If you are a shop owner, you are making your money off of employees selling their labor to you for a designated wage. You are not therefore working class. By thinking that you'd be joining the working class in their resistance to class exploitation by claimng that you too are part of their struggle, and thus they should give you their money, would be furthering the manipulation and exploitation they face. Coffee in general is a luxury, and especially if it's high end specialty stuff. Also, quality is largely overrated. The majority of people who consume things don't care about quality precisely because they don't have the luxurious privilege to do so.
Not every example of differences between the working and ruling class is an example of intentional resistance. Grammar and other conventions are learned through culture regardless of what class you grow up in. Just the same, the people in ruling classes don't always intentionally rule over the people in the working class. The power dynamics at work are a bit more vicarious than you are giving credit for. Just some thoughts to consider.