It is reasonable, but it's also reasonable to factor in the actual situation, which is that tipping is the norm in the US. You can either make the coffee $3.60

It is reasonable, but it's also reasonable to factor in the actual situation, which is that tipping is the norm in the US. You can either make the coffee $3.60 - and seem more expensive than the place next door - or you can make it $3 and assume everyone tips. Also, if you make it $3.60, everyone will still try to tip.