Comment by kshacker

From someone who lives in bay area (so not <4k), this is exceedingly common. Of course Walmart does not have a small business owner on-site who can oversee such adjustments, but think mom and pop / single owner stores. They do it all the time.

Think contractors. They also do it all the time. When I did a remodel a couple of years back, he asked for cash. It was a small amount so I did not think much until my accountant told me I will need receipts if I wanted them added to my house's capital /cost. I asked the contractor and he stalled me for weeks while also saying I will need to pay more for receipts, until one day I forgot chasing (and am thinking of it now) and just let it go I guess.