But if you use it for yourself and you pay a fair amount, say production+shipping+administration, you are not really making a benefit.

Say a store has a stereo on sale for $300 and you decide that since the wholesale price was only $120, a fair price would be $150. You're saying as long as you plan to use it personally, you could lay down three fifties and walk out with it without 'benefiting'? Your benefit in that case would be the $150 you avoided paying.

You get the licence plate. That's the benefit. You didn't have it before, you have it now, it's something someone (incl you) value. "benefit" doesn't mean "profit".