Rich,
You make some valid points, bear in mind that waiting in line is not the only thing a NIS does.
You can add to that billing, packing, shipping, trips to the post office, bookeeping and hopefully collecting ALL your money in a timely fashion.
Also bear in mind, as you said above, sometimes there are multiple chips and several denominations which also carry a large cash outlay, so add to that cost of money.
To all this you can also add gas and parking where applicable not to mention driving time. [unless you are lucky to be a local].
There are also times when several casino's issue chips or there are limits where you have to pay someone to stand in line
Total up the amount of time involved and unless you have a LARGE list of customers you could probably make out better learning phrases such as "would you like extra fries withthat sir"

I will just say I'm glad someone is doing the legwork for me.