I hate this point, so what? It's not like the lower class in "pick you region of interest" can take advantage of this localized price disparity. The poor person is poor based on their spending power with respect to the local economy and its pricing.
Using this example: a computer was an unlikely purchase for a lower-middle class person in the US, but it wasn't totally unattainable. Many people in the US probably did it, and some of them probably found some positive return on that investment.
That's not true of many "objectively" poor people in the world, who even if they could buy the computer, they might not have had access to electricity to run it.