I see a transfer as basically being straight profit for half an hours work. Just have to log the gun and run a background check.
It would require pretty good accounting to get to that result. He's paying insurance, rent, taxes, utilities etc. which creates an hourly cost, and hopefully they make something to feed the family. Not to mention things like depreciation. So for 30 minutes, maybe less, he's tied up doing your stuff. If they charge $25 (seems about average around here) that's $50/hour gross, subtract out the cost per hour previously identified and you get the amount left to buy groceries for the kids (after income tax of course).
They are lucky to be making $15 an hour after all that. Now if you can get it down to 5 minutes, and do 100 transfers a day it might make business sense.