DDR3 in 2021?

Question

RAM

There is a laptop of 2020 (October), I bought it during the iron crisis. A bargain purchase is certainly not called, but a laptop was needed. On board:

Athlon Silver 3050U
SSD NvME 128 GB
DDR4 2333 mhz 4 GBx1PCS

Notebook model IdeaPad 3 14ADA05, supports only 1 memory slot.

Obviously, there is not enough memory, I decided to buy DDR4 memory, but due to the support of only the 1st memory slot, a tidy sum comes out (On average, from 3200r to 4400r, on Ali without delivery, taking into account the exchange rate). On hand only 2000r, in my head the idea is to take DDR3, because. cheaper, but not sure about the relevancy of the purchase.

Answer 1

DDR3 and DDR4 are not compatible with each other. You can’t even put it on, the key won’t allow it.

Answer 2

They have different sizes, there is no way you can put DDR3 in a DDR4 slot

Answer 3

DDR3 and DDR4 are completely different modules.
It is better to dig and install a normal DDR4 module.