I know people are talking about how you should buy the additional RAM upfront but sometimes either that specific variant with more RAM is not available or there is some very good sale going on but it doesn't apply to the model with more RAM, so the perceived cost of the added RAM is just too big for the desired model of the computer laptop, making it hard to go with the decision of acquiring it.

If this was a service available from repair shops, I could see people making the math and going for it sometimes.