Then there's the other side of the rule spectrum.
There is a Canadian store with branches all over Mexico called Coppel. I am convinced that although Coppel has many big and small ticket items for sale, it is much more interested in loaning money at extreme rates than in selling anything. Downstairs are refrigerators, washing machines, and TVs. Upstairs are smaller but expensive items like sewing machines, blenders, microwaves. They have all the other stuff a kitchen needs too, pots and pans, spatulas, etc. Everything in the store has a very professional sign on it with two prices. The price you pay weekly, or the price you pay in cash. For a refrigerator that costs 5,000 pesos in cash, the long term payment over 100 weeks will cost the customer 10,000 pesos total. (But you'd have to be able to multiply 100 pesos by 100 weeks to know that!) It's an interest rate of 50% a year!!!
Even a 26 peso spatula has a payment plan. The small items are secured, hanging from locked studs. I had seriously looked around the cheaper hardware and miscellaneous stores for a small skillet and spatula, but found what I really wanted at Coppel. Both were locked up. Nobody who worked there seemed to be able to unlock them and they told me to ask at the payment window (where 30 people were lined up to pay their weekly 100 peso installments) for a "muchacho". I asked and nobody showed up. After about ten minutes I found a kid in a store uniform shyly skulking around behind some displays. I asked if he could help me and he looked embarrassed that I'd caught him doing nothing at all. He followed me to the items, wrote the numbers on a piece of paper and then took me downstairs to pay while he then went back upstairs to unlock and fetch them. Why he couldn't have unlocked them and brought them down with us, I don't know. More than likely it's a rule of some kind, like you can't let a customer see how easy it is to unlock something.
So downstairs I pulled out a 100 peso bill and was ready to pay for my two items. (100 pesos is the equivalent to $8 US dollars!) The woman slowly and meticulously filled out a form on the computer. She needed my name, my address, my birthdate, my phone number. What? I refused. She became visibly upset. I told her I was paying cash and asked why she needed all that? She looked blank. I'm sure she was just trying to fill out the form because that's her job and those are the rules. Finally she reluctantly took the money and a bit later the muchacho showed up with my purchases in a bag, stapled at the top.