Discounts on gadgets to everyone

On Habré every day a lot of news about gadgets is published. For me, at least, they fall into the following categories:

• Gossip
• Coming soon
• Appeared and I already bought
• Appeared in Russia. Expensive!
• Here it is!

I want to touch on item number 4, namely: how it is legal for one and all to receive a discount on any gadget available in retail chains.
Credits are evil. So usually consider two categories of the population: those who took out a loan, and their children.
In fact, credit is a good savings tool. The point is this: you have the required amount for any iPad, for the convenience of the account we take the price of 24,000 rubles.
What happens if we just buy a product?
We pay 24,000 rubles at once and use it for health.
Now we use installments, about which there is a lot of advertising on TV: [0% down payment, 0% percent, 24 months] (there are several companies and banks offering this pleasure - Yandex to help).
Then it looks like this:

month	payment
0
one	1,000
2	1,000
...	1,000
24	1,000
total	24,000

At the same time, if you read the conditions for providing installments, you can see somewhere under the asterisk "... the loan rate is so many percent per annum ...". This means that you still take out a loan, and a loan is not an installment plan. The conditions for the loan are as follows: a monthly payment of 1,000 rubles, a term of 24 months (i.e., you actually pay the same initial 24,000 rubles), but the rate, for example, is 8.11%.
How come? The monthly payment (annuity) of 1 000 rubles consists of 2 components: interest on the loan and the loan body. And every month they are in such proportion that the same value is obtained, in our case - 1000 rubles.
Taking into account the rate and term (see above), it can only look like this:

month	payment	body	%
0
one	1,000	851	149
2	1,000	857	144
....	1,000	...	...
23	1,000	987	13
24	1,000	993	7
total	24,000	22,087	1 914

The attentive viewer will realize that the sum of all payments on the body is equal to 22,087 rubles, this is the amount of the loan.
It turns out that the goods worth 24,000 rubles you actually buy for 22,087 rubles. This is no less than a discount of 8% (why this makes the store as a whole understandable, but this is not the subject of this post, the question can be opened in the comments).
However: you do not buy, but take on credit, for 24 months, at a rate of 8.11%, and after 2 years this is 24,000 rubles. On the one hand, there should already be savings here: 24,000 rubles today and 24,000 rubles in 2 years is a different 24,000 rubles (cash discount). Although, of course, not everyone indexes their salaries!
What's next? We read the terms of the loan agreement. Depending on the bank that provides the service, it is possible to repay the loan early. In my example, this can be done after 3 months of using a loan. We are waiting for 3 months and extinguish:

month	The balance of the principal (body)	payment
0
one	22,087	1,000
2	21,236	1,000
3	20 380	1,000
four	19,517	19,649
total		22,649

Now it turns out that you are buying goods worth 24,000 rubles for 22,649 rubles.
This is a 5.6% discount.
Just.
More and pay all at once is not necessary.
(Shine, gorgeous).
Information for those who are few.
With installments there is an amount of 19,649 rubles, which you only have to pay in the 4th month. We put them on a term deposit of 3 months (for example, 9% per annum). This is (19,649 * 0.09) / 4 = 442 rubles.
Findings:

	Purchase immediately	Purchase under the scheme
Owning a gadget	From the first day	From the first day
A discount	0%	5.6% *
Additional income from operations	0 rubles	Deposit income from the amount of early repayment of the loan **
Positive credit history ***	not	Yes

* depends on the loan rate (see article)
** depends on current market offers (see market)
*** in fact, the factor is significant, as advanced banks already offer products with a rate that depends on the quality of the borrower. Good credit history = good borrower.
In my opinion, the choice is obvious.