A few years ago the California DMV offered online credit card payments of registration fees, and charged a $4 (I think) "convenience fee". Their argument was that they were mandated by law to collect specified fees for specified services, and the merchant charges would reduce what they collected below the statutory amount. (Apparently the cost of clerks to handle checks received in the mail did not have the same effect ) . I guess noone was taking them up on their "offer" (a first class postage stamp is a lot less than $4), and they have since dropped the "convenience fee" on the online payments.
I wouldn't say that an area where the mall has stores like Louis Vitton, Hugo Boss and Gucci is a "seedier" area.