I got some arduino nano replicas on aliexpress a couple of months ago for an incredibly low price. Not surprisingly, there was a reason for the discount. The pin assignments as they’d be programmed in the IDE did not match the pins as they were silkscreened on the board. The analog pins were silkscreened in reverse order to their actual hardwired positions.
Thus, among the plethora of reasons that a device might end up super cheap on ali-x are manufacturing defects. This problem happenned to just be with the silkscreen, but the silkscreen is a very important time saver for circuit assembly.
Nevertheless, the board I used still helped me blast together a device to run an experiment and log data. The physical chemistry involved has been more problematic than anything else for that experiment, but a change in approach will eliminate all such problems.